-^?*lfe 


7^ 


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CJ 


Experimental    Psychology 

AND    ITS    BEARING   UPON 
CULTURE 


BY 


GEORGE  MALCOLM  STRATTON 

M.A.,  Yale;    Ph.D.,  Leipzig 

AflSQCXXTE   PROFESSOR  OF  PSYCHOLOGY  AND  DIRECTOR   OF  THE   PSYCHOLOGICAL 
LABORATORY  IN  THE   UNIVERSITY   OF   CALIFORNIA 


I^NIVERSJTY 


OF 


^iir[Fos:-!\ii 


7kx^^ 


THE   MACMILLAN   COMPANY 

LONDON:  MACMILLAN  &  CO.,  Ltd. 
1903 

Ai^  rights  reserved 


fjv 


Copyright,  1903, 
By  the  MACMILLAN  COMPANY. 


Set  up  and  electrotyped  April,  1903. 


NorfaoolJ  i3rp08 

J.  8.  Gushing  &  Co.  —  Berwick  &  Smith  Co. 

Norwood,  Mass.,  U.S.A. 


PREFACE 

The  aim  of  the  present  volume  is  to  give  an  un- 
technical  account  of  certain  groups  of  experiments 
in  psychology  and  to  show  something  of  their  signifi- 
cance. As  to  the  particular  experiments  that  are  of 
most  interest  and  importance  in  this  field,  of  course 
opinions  would  differ.  Every  one  who  works  in 
psychology  soon  finds  himself  attracted  in  special 
directions,  and  on  the  whole  it  is  perhaps  well  for  a 
writer  to  respect  this  element  of  personal  affinity. 
But  in  preparing  the  book,  I  have  aimed  to  present, 
as  best  I  could  within  somewhat  narrow  limits,  the 
character  and  value  of  the  laboratory  psychology, 
especially  as  bearing  upon  our  moral  and  philosoph- 
ical interests.  In  this  way  the  book  is  planned  to 
occupy  a  different  field  from  that  already  so  well 
covered  by  the  excellent  works  of  Titchener,  San- 
ford,  and  Scripture. 

Considerable  attention  has  thus  been  given  to  the 
interpretation  of  the  experimental  results,  —  to  their 
more  immediate  scientific  meaning,  as  well  as  to 
what  they  suggest  for  life  and  for  speculation.  But 
first  and  foremost  the  purpose  has  been  to  get  the 
experiments  themselves  clearly  before  the  reader,  so 
that  the  main  features  of  the  research  work  might 


^  o  R  n '"' 


vi  Preface 

be  seen  concretely.  Many  of  the  experiments  thus 
described  are  already  familiar  to  students  of  psy- 
chology, but  a  number  appear  here  for  the  first  time. 
It  would  be  difficult,  if  not  impossible,  to  tell  in 
detail  of  my  obligation  to  others.  I  cannot  forbe5.r 
to  mention,  however,  the  Council  and  members  of  the 
Philosophical  Union  of  the  University  of  California, 
who  some  years  ago  invited  me  to  speak  to  them 
upon  the  character  and  import  of  psychological  ex- 
periments, and  to  whose  interest  and  encouragement 
the  present  volume  largely  owes  its  existence.  I  am 
also  particularly  grateful  to  my  friend.  Professor 
Bakewell,  who  has  kindly  read  the  book  in  proof, 
and  has  given  me  throughout  most  helpful  advice. 
In  preparing  the  chapters  dealing  with  the  psy- 
chology of  Esthetics  I  have  received  great  benefit 
from  the  criticism  of  my  friend,  Mr.  Frederic  C. 
Torrey,  and  I  am  indebted  to  my  colleague.  Dr.  Mon- 
tague, for  similar  aid  in  regard  to  certain  problems  of 
Space.  For  the  photographs  required  in  many  of 
the  illustrations  I  must  thank  Mr.  Brand,  the  former 
Assistant  in  the  Laboratory,  and  Mr.  Dunlap,  the 
present  Assistant.  There  is  a  more  general  indebted- 
ness to  my  honored  teacher.  Professor  Wundt  of 
Leipzig,  who  introduced  me  to  the  experimental 
work.  But  I  owe  most  of  all  to  my  teacher  and 
friend.  Professor  Howison,  to  whom  I  should  have 
been  glad  to  dedicate  affectionately  this  book  were 
I  not  so  fully  conscious  of  its  shortcomings. 


CONTENTS 

CHAPTER  PAGE 

I.     Historical  Introduction i 

II,     The  General  Character  of  Psychological  Experiments  17 

III.  The  Possibility  of  Mental  Measurements         .         .  33 

IV.  The  Evidence  for  Unconscious  Ideas      ...  66 
V.     Further  Considerations  as  to  the  Unconscious         .  82 

VI.     Illusions  and  their  Significance       ....  95 
VII.     Experiments  on  Mental  Space,  particularly  the  Space 

of  the  Blind 122 

VIII.     The  Harmonies  and  Discords  of  Space  Perception, 

and  its  Place  in  Experience 142 

IX.     Memory  and  the  Influence  of  Time         .         .         .  165 
X.     Temporal  Signs  and  the  Rank  of  Memory       .         .185 

XI.     Imitation  and  Suggestion 199 

'^  XII.     The  Enjoyment  of  Sensations  and  their  Forms       .  227 

XIII.  Color  and  the  Diff'erentiation  of  the  Fine  Arts         .  249 

XIV.  The  Connection  of  Mind  and  Body         .         .         .262 
XV.     Spiritual  Implications  of  the  Experimental  Work  .  295 

Index 3^5 


Vll 


CHAPTER  I 
HISTORICAL  INTRODUCTION 

Only  within  a  few  years  has  it  been  generally  The  roots 
known  that  experiments  on  the  mind  were  being  °NewPsy- 
attempted.  Doubtless  the  whole  subject  has  still  for  choiogy." 
some  an  air  of  novelty  and  perhaps  almost  of  fad- 
dishness,  as  if  it  had  sprung  into  life  but  yesterday 
and  would  pass  away  to-morrow.  But  the  fact  is, 
that  like  so  many  things  that  suddenly  catch  the 
public  eye,  the  days  of  its  growth  have  been  long 
and  quiet,  and  the  suddenness  is  not  of  its  appear- 
ance but  only  of  noising  its  fame  abroad.  For  just 
as  Darwinism  was  germinating  in  the  days  of  Hera- 
clitus,  so  we  can  now  discover  the  premonitions  of 
what  is  often  called  the  "New  Psychology"  at  least 
as  early  as  Aristotle.  He  performed  experiments  in 
psychology,  and  ever  since  his  time  traces  of  such 
work  can  be  found.  The  modern  turn,  then,  is  not 
in  discovering  the  possibility  of  psychological  experi- 
ments, but  in  becoming  distinctly  conscious  of  their 
value,  —  in  utilizing  them,  therefore,  to  a  greater 
extent  and  in  developing  something  like  a  critical 
procedure  in  carrying  them  out. 

To  understand  the  motives  that  have  led  to  the  Reasons  for 
laboratory  work  in  psychology  one  must  recall  that  ^^^  growth. 
for  centuries   the   peculiar  and   solitary  method  of 


2  Experimental  Psychology- 

getting  at  the  facts  of  mind  was  supposed  to  be  that 
of  self-observation,  or  of  introspection,  as  it  is  more 
frequently  called.  Whether  we  recognize  the  method 
by  name  or  not,  it  certainly  is  one  with  which  all  are 
familiar.  You  can  probably  tell,  for  instance,  whether 
the  thought  of  territorial  expansion  beyond  the  seas 
meets  your  approval,  or  whether  you  view  it  with 
mingled  consent  and  distrust,  or  perhaps  with  un- 
mixed regret.  This  direct  acquaintance  with  the 
state  of  our  minds  which  all  of  us  to  some  extent  pos- 
sess, is  the  essence  of  introspection,  and,  as  I  have 
said,  was  for  centuries  the  only  recognized  mode  of 
collecting  the  data  of  psychology.  The  psychologist 
turned  his  mental  gaze  inward,  and  reported  as  best 
he  could  what  he  there  observed.  The  objects  of 
this  science  were  supposed  to  be  noted  by  some  inner 
sense,  in  contrast  with  our  eyes  and  ears,  with  which 
we  observe  external  objects,  the  materials  for  the 
familiar  natural  sciences. 
Difficulties  Now   it  can   be  pretty   clearly   shown   that  self- 

tiom*'^°^^^^"  observation  must  always  be  the  fundamental  method 
of  psychology;  it  permits  the  initial  step  and  fur- 
nishes us  with  all  the  really  first-hand  knowledge  of 
the  mental  world  that  we  possess.  But  for  all  that, 
one  must  not  fail  to  recognize  the  historical  fact  that 
psychology,  as  long  as  it  relied  solely  on  this  method, 
was  at  a  striking  disadvantage  compared  with  the 
natural  sciences  generally.  In  the  first  place,  the 
posture  of  introspection  is  cramped  and  unnatural. 
^  We  are  practical  beings  and,  if  we  are  healthy,  life 

has  trained  us  to  be  interested  in  things  beyond  our- 
selves.   The  habit  of  self-observation,  if  not  a  morbid 


Historical  Introduction  3 

trait,  as  in  Amiel  or  Marie  Bashkirtseff,  is  at  least 
artificial,  and  tends  to  throw  the  whole  mental  train 
off  the  track.  Try,  for  instance,  to  be  deeply  inter- 
ested in  what  some  one  is  saying  to  you,  and  at  the 
same  time  to  scrutinize  and  report  to  yourself  how 
it  feels  to  be  deeply  interested.  Many  of  our  most 
important  mental  states  positively  refuse  to  be  gazed 
at  in  this  way;  they  elude  our  direct  scrutiny,  and 
the  best  we  can  do  is  —  paradoxical  as  it  sounds  — 
to  recall  how  they  looked  when  we  were  not  looking  at 
them.^  Compared  with  those  sciences  whose  materials 
are  absolutely  indifferent  to  any  amount  of  weighing 
and  grinding  and  heating  and  examination,  one  can 
well  understand  how  the  progress  of  psychology  was 
inevitably  slow  and,  to  some  extent,  disappointing. 
Moreover,  there  is  something  peculiarly  private  and 
incommunicable  in  every  fact  of  mind.  We  cannot,  as 
a  mineralogist  may,  hand  around  our  particular  speci- 

1  This  fugitive  character  of  many  of  our  mental  states  has  often 
been  pointed  to  in  proof  of  the  impossibility  of  introspection.  The 
truth  of  course  is,  that  only  by  means  of  introspection  do  we  know  that 
our  mental  processes  are  changeable  and  elusive.  It  is  curious  that 
when  critics  like  Maudsley,  at  least  in  his  earlier  writings,  make  such 
short  work  of  self-observation  as  a  psychological  method,  they  do  not 
see  that  most  of  the  facts  they  bring  forth  as  evidence  of  its  funda- 
mental inadequacy  are  obtained  only  by  this  very  self-observation. 
They  trust  their  own  introspection  in  its  report  that  the  mental  life  is 
always  in  flux,  that  attention  to  our  mental  processes  alters  their  char- 
acter, etc.,  and  then  argue  that  this  discredits  the  whole  procedure ; 
whereas  these  very  results  show  that  the  method,  within  certain  limits, 
is  the  readiest  and  most  reliable  we  have. 

Such  criticisms  also  invariably  dwell  on  those  mental  processes  (the 
emotions,  for  instance)  that  are  most  liable  to  interruption  if  we  attend 
to  them,  and  cannot  well  be  repeated  at  will,  and  leave  out  of  account  the 
many  processes,  such  as  perceptions  and  judgments  and  certain  memory- 
images,  that  can  be  repeated  and  observed  with  great  security. 


Experimental  Psychology- 


Desire  for 

"objective" 
methods. 


men  of  judgment  or  volition,  and  ask  others  to  verify 
the  results  of  our  examination  of  it.  The  results  of 
self-observation  consequently  seem  to  be  personal  and 
*' subjective,"  and  lacking  in  that  universality  which 
is  the  pride  of  chemistry  and  of  physics.  It  was  to 
be  expected,  then,  that  there  would  be  a  longing  for 
some  mode  of  investigation  wider  in  its  application 
and  more  fruitful  than  self-observation,  and  that  in 
due  time  there  would  be  an  organized  revolt  in  favor 
of  "objective"  methods,  among  which  the  experimen- 
tal procedure  was  to  have  an  important  place. 


Influence  of 
British 
empiricism. 
Bacon  to 
Hume. 


Berkeley's 
psychology 
of  space. 


The  present-day  experimental  study  of  mind  is  but 
the  latest  development  of  that  scientific  movement 
of  which  Francis  Bacon  was  chief  spokesman.  Bacon 
led  to  Hobbes,  with  whom  there  began  the  strong 
empirical  movement  in  psychology  in  the  seventeenth 
and  eighteenth  centuries,  to  which  our  present  meth- 
ods of  investigating  the  mind  owe  so  much.  The 
English  were  the  first  to  become  interested  in  psy- 
chology for  its  own  sake.  On  the  continent  it  had 
always  been  a  secondary  matter,  a  mere  appendage 
to  metaphysics ;  whereas  the  English,  in  Locke  and 
Berkeley  and  Hume,  almost  reversed  the  order  and 
made  metaphysics  a  subordinate  chapter  of  psy- 
chology. At  any  rate,  the  facts  of  our  everyday 
mental  life  at  last  came  to  their  own,  and  in  the 
writers  just  mentioned  some  of  the  chief  problems 
of  the  experimental  work  began  to  be  mapped  out. 
Berkeley's  remarkable  "  Essay  toward  a  New  Theory 
of  Vision  "  shows  a  distinctly  modern  attitude  toward 
psychology,  which  at  that  day  it  would  indeed  be  diffi- 


Historical  Introduction  5 

cult  to  parallel.  He  states  the  particular  question, 
how  we  are  able  to  discern  by  sight  the  size  and  dis- 
tance and  shape  of  objects  ;  and  after  a  masterly  array 
of  facts  and  arguments,  comes  to  his  well-known  con- 
clusion that  none  of  these  aspects  of  things  is  given 
us  by  vision  alone  and  of  itself,  but  only  by  vision  in 
conjunction  with  our  sense  of  touch.  Not  until  we 
are  able  to  translate  our  impressions  of  sight  into 
terms  of  touch  and  muscular  movement,  does  our 
vision  come  to  mean  for  us  anything  spatial.  If 
history  had  been  as  silent  in  regard  to  the  life  and 
time  of  Berkeley  as  it  is  about  the  personality  of 
Shakespeare,  not  only  his  theory  but  also  the  man- 
ner in  which  he  supports  it  might  have  given  excel- 
lent grounds  for  some  clever  critic  to  claim  that  the 
good  bishop  had  merely  lent  his  name  to  the  produc- 
tion of  some  shy  disciple  of  Helmholtz  or  of  Wundt. 
So  far  as  I  am  aware,  Berkeley  gives  the  first  instance 
of  a  problem  of  psychology  being  thus  disentangled 
and  honored  with  a  special  and  purely  psychological 
treatise. 

As  if  to  furnish  the  experimental  verification  which  Surgeons' 
Berkeley  himself  recognized  was  needed  for  his  theory,  ^^estlbS^*^ 
there  soon  appeared  the  first  of  a  series  of  contribu-  view. 
tions   by  various   physicians   in   the    "Philosophical 
Transactions  of  the  Royal  Society  of  London,"  giv- 
ing the  results  of  experiments  on  persons  operated 
upon  for  congenital  cataract.     The  most  celebrated 
case  was  that  reported   by  Cheselden  in   1728,  and 
this   was   followed    by   others    from    Home,   Ware, 
Wardrop,  and  many  besides.     If   Berkeley's  theory 
were  correct,  then  a  person  gaining  his   sight   sud- 


6  Experimental  Psychology 

denly,  as  these  patients  for  the  most  part  did, 
ought  not  to  be  able  to  discern  the  shape  or  dis- 
tance or  direction  of  objects  by  sight  alone,  but 
only  by  sight  working  in  combination  with  touch. 
A  number  of  tests  were  accordingly  made,  the  de- 
tailed discussion  of  which  will  come  more  appro- 
priately in  a  later  chapter.  Here  it  is  sufficient  to 
say  that  the  results  have  generally  been  considered 
as  strongly  in  favor  of  Berkeley's  theory;  but  this 
interpretation  is,  I  think,  open  to  question,  and  needs 
a  careful  review.  The  interesting  fact  in  the  present 
connection,  however,  is  not  whether  the  evidence  he 
offered  is  adequate  or  inadequate,  but  that  Berkeley 
and  a  large  body  of  men  recognized  in  this  practical 
way  that  there  were  important  psychological  problems 
which  were  to  be  decided,  not  by  the  traditional  in- 
trospective method,  but  by  external  and  experimental 
means. 
Place  of  the  We  may  pass  by  the  later  English  development  in 
S"sociation-  Hartley,  James  Mill,  John  Stuart  Mill,  and  Spencer.  It 
ists.  is  of  great  importance  for  the  history  of  psychology 

in  general,  but  not  for  the  growth  of  the  experimental 
side.  These  men  were  system-makers,  interested 
most  of  all  in  working  out  what  seemed  to  them  to 
be  the  one  great  explanatory  principle  in  psychology, 
—  the  principle  of  association.  It  is  well  that  there 
are  such  men,  who  feel  that  the  subordinate  questions 
of  a  subject  are  to  be  answered  by  learning  the  com- 
mon secret  of  the  whole.  But  experimental  psy- 
'  chology  is  indebted   perhaps   more   to   those  whose 

interests  run  to  the  opposite  pole,  —  who   feel   that 
the  search  for  the  secret  of  the  whole  may  be  de- 


Historical  Introduction  7 

ferred  until  we  know  more  about  the  subordinate 
parts  of  that  whole.  Wisdom  is  doubtless  justified 
of  both  kinds  of  children.     But  it  is  easy  to  see  that  . 

when  the  English  psychological  activity  turned  more 
and  more  to  buttressing  up  a  system,  the  atmosphere 
there  grew  less  stimulating  for  the  other  kind  of  work. 
Germany,  on  the  other  hand,  was  running  exactly  the  TheGer- 
opposite  course.     The  Germans,  after  their  long  line  ^f^j^g^I-^^^ 
of  philosophers  from  Leibnitz  to  Hegel,  were  at  last  physics, 
coming  to  the  point  which  England  and  France  had 
reached  long  before, — were  losing  faith  in  philosophy 
altogether,  and  were  preparing  to  attack  the  problems 
of  mind  from  the  other  side. 

But  in  Germany,  as  in  England,  the  interest  in  the 
experimental  study  of  consciousness  was  not  developed 
entirely  from  within  the  ranks  of  the  psychologists 
themselves.     Goethe,   for  instance,  was   among   the  Goethe's  ex- 
early   experimenters   in   psychology.     He   made   an  ^^[^"co^or 
interesting  study  of  the  influence  of  color  upon  the 
emotions,  by  observing  the  landscape  through  glasses 
now  of  one  color  and  now  of  another,  and*  noting  the 
contrasting  moods  induced   by  the   different   hues.^ 
And  some  experiments  which   bear  a  much   closer  Psychoiog- 
connection   with   the   direct   historical    development  J^g^Jg^^^^^' 
came  indeed   from  the  astronomers,  brought  about,   astronomers, 
of  course,  not  by  any  special  interest  in  psychology, 
but  by  the  practical  needs  of  their  observatory  work. 

According  to  the  older  method  of  determining 
the  time  when  a  star  reached  its  meridian,  the  ob- 
server watched  the  passage  of  the  star  through  the 
field  of  his  telescope,  and  at  the  same  time  Hstened 

1  Farbenlehre,  §§  769,  784,  798. 


8 


Experimental  Psychology 


Determina- 
tion of  "per- 
sonal equa- 
tion." 


Influence  of 
the  physiolo- 
gists. 


to  the  beats  of  a  clock  near  at  hand.  As  the  criti- 
cal moment  approached,  he  had  now  to  perform  the 
somewhat  difficult  task  of  noting  at  what  instant  in 
the  series  of  pendulum  beats  the  passage  of  the  star 
across  the  meridian  (marked  by  a  hair-line  in  the 
field  of  the  telescope)  actually  occurred.  To  do  this 
accurately  he  must  tell  not  merely  at  which  beat  of 
the  clock  this  transit  took  place,  but  since  the  transit 
usually  occurs  somewhere  between  two  beats,  he  must 
determine  the  more  exact  fraction  of  a  beat  which  had 
elapsed  when  the  star  reached  the  meridian.  This  was 
the  "eye  and  ear"  method,  now  discarded,  by  many 
astronomers,  for  the  chronograph  with  its  electric 
recorders.  The  astronomer  Bessel  noticed  as  early 
as  1822  that  when  different  persons  observed  the  very 
same  fact,  there  were  discrepancies  which  could  be 
accounted  for  only  by  the  different  make-up  of  the 
observers  themselves.  And  experiments  were  accord- 
ingly instituted  to  determine  what  has  since  come  to 
be  known  as  "personal  equation."  All  this  was  a 
psychological  matter,  and  the  experiments  that  gave 
some  light  on  the  question  were  psychological  experi- 
ments, even  though  carried  on  from  an  interest  pri- 
marily in  quite  a  different  field.  Out  of  these  has 
grown  an  important  group  of  laboratory  investi- 
gations in  what  is  called  reaction-time,  of  which 
more  will  be  said  in  a  later  chapter. 

But  the  work  which  had  a  more  direct  influence  in 
developing  systematic  experimentation  in  psychology 
came  from  the  physiologists,  especially  from  those 
who  were  interested  in  the  sense-organs.  Any  one 
who  will  turn  the  pages  of  the  particular  volumes  of 


I 


Historical  Introduction  9 

Hermann's  "  Hand-book  "  that  are  devoted  to  the 
subject,  will  see  how  many  experiments  were  early 
carried  on  to  discover  primarily  the  function  of  the 
sense-organs,  but  which  in  so  doing  laid  bare  much  of 
the  psychology  of  our  sense-perception.  Probably 
few  besides  professional  students  appreciate  the  fact 
that  much  of  Helmholtz's  labors  lay  on  the  psycho-  Heimhoitz's 
logical  side  of  the  border  between  physiology  and  K^cai  work 
psychology,  and  that  he  may  be  claimed  for  either 
science.  His  great  works  on  "  Physiological  Optics  " 
and  on  "  Sensations  of  Tone  "  are  stores  of  psycho- 
logical material  gathered  in,  for  the  most  part,  through 
Heimhoitz's  own  genius  for  devising  and  carrying  out 
experiments  in  this  field.  And  there  were  many  other 
pioneers  in  the  same  region.  Vierordt,  for  example, 
more  than  half  a  century  ago,  made  an  experimental 
study  of  our  sense  of  time  —  a  field  of  investigation 
since  then  diligently  worked  in  the  modern  labora- 
tories. And  almost  with  apologies,  one  ought  to  men- 
tion the  phrenologists,  Gall  and  Spurzheim.  Unscien-  Phrenology 
tific  as  the  whole  spirit  of  these  men  was,  their  curious  brai^iocaS 
system  undoubtedly  did  much  to  stimulate  those  later  zation. 
experiments  regarding  the  connection  between  brain 
and  consciousness,  that  led  to  the  briUiant  discoveries 
in  the  "localization"  of  mental  function,  with  which 
the  names  of  Broca,  Goltz,  Ferrier,  and  many  others 
are  connected.^ 

1  The  more  physiological  aspects  of  psychology  are  considered  at 
some  length  in  the  chapter  on  "The  Connection  of  Mind  and  Body." 
There  is  an  excellent  sketch  of  the  growth  of  this  neural  work  by 
Dr.  Henry  Smith  Williams  in  an  article  entitled  "  The  Century's 
Progress  in  Experimental  Psychology,"  in  Harper's  Magazine  for 
September,  1899,  Vol.  99,  p.  512. 


lo  Experimental  Psychology 

The  immedi-       When  we  try  to  trace  out,  however,  not  so  much 
ate  parentage  ^^    various  distant  sourccs,  but  the  immediate  parent- 

of  experi-  '  ^ 

mental  age  of  experimental  psychology,  one  must  name  first 

psychology,  ^j  ^j^  g^.^^^  Hcinrich  Weber.  With  him  there  begins 
what  we  might  call  an  unbroken  experimental  tradi- 

E. H.Weber,  tion.  Up  to  Wcbcr's  time  {^\^  floruit  is  well  along 
in  the  second  and  third  quarters  of  the  nineteenth  cen- 
tury), and  even  with  many  who  outlived  him,  psycho- 
logical experiments  were  carried  on  sporadically  and 
without  much  appreciation  of  their  true  significance. 
Weber,  however,  aroused  an  interest  not  only  in  his 
results,  but  even  more  in  the  experimental  method 
by  which  his  results  were  obtained.  He  made  men 
recognize  experimentation  as  a  mode  of  procedure 
for  psychology,  —  a  recognition  which  since  his  time 
has  gradually  become  clearer  until  now  it  is  no  longer 
open  to  doubt.  So  that  the  historical  importance  of 
Weber's  experiments  quite  overshadows  their  in- 
trinsic interest.  But  his  contributions  so  enter  into 
the  after-Hfe  of  the  subject,  and  in  teUing  of  his 
successors  one  must  so  often  refer  to  Weber's  Law, 
that  it  will  perhaps  be  well  to  go  somewhat  into 
detail  at  this  point,  even  at  the  risk  of  seeming 
prolix. 

Character  In  these  experiments  the  more  immediate  purpose 

was  to  determine  the  relative  sensitiveness  of  differ- 
ent parts  of  the  skin,  probably  with  some  apprecia- 
tion of  the  value  of  such  tests  for  the  physician.  In 
certain  nervous  diseases,  for  instance,  the  symptoms 
are  in  part  a  lowering  or  heightening  of  the  sense  of 
touch,  and  the  character  and  extent  of  the  disease 
are  indicated  by  comparing  the  sensitiveness  of  the 


of  his 
experiments 


I 


Historical  Introduction  ii 

patient  with  that  of  a  normal  person.  Weber  arrived 
at  a  table  of  this  normal  sensitiveness  and  its  varia- 
tions for  different  parts  of  the  body,  experimenting 
with  compass  points  and  with  weights. 

But  more  important,  judged  by  the  amount  of  dis- 
cussion they  set  going,  were  his  experiments  on  our 
power  of  comparing  different  weights  on  the  skin. 
His  tests  here  led  him  to  discover  an  interesting  bit 
of  relativity.  He  placed  a  standard  weight  of  32 
drachms  on  his  hand  and  found  that  an  addition  of 
about  10  drachms  made  the  weight  sensibly  heavier. 
But  when  he  used,  instead,  a  standard  weight  of  32 
ounces  (eight  times  heavier  than  the  former  standard) 
the  same  absolute  addition  of  10  drachms  was  no 
longer  detected,  but  he  must  make  the  same  relative 
addition,  namely  10  ounces,  before  the  weight  was 
noticeably  increased.  Stated  as  a  general  proposition, 
appHcable  not  only  to  weights  and  pressures,  but  to 
all  our  perceptions,  this  becomes  the  famous  formula 
known  as  Weber's  Law,  that  our  power  of  detecting  His  law 
differences  between  sensations  does  not  depend  on  °ation""™^' 
the  absolute  amount  of  difference  in  the  stimuli,  but 
on  its  relative  amount.  And  although  some  might 
believe  that  it  did  not  require  experiments  to  show 
so  obvious  a  truth,  yet  later  researches  have  demon- 
strated that  it  is  by  no  means  so  obvious  after  all, 
and  that  there  are  considerable  stretches  of  our  mental 
life  where,  if  the  law  does  hold  good,  something  at 
least  interferes  with  its  clear  manifestation. 

One   of   the   most  important   results   of   Weber's  Fechnerand 
experiments,  however,  was  their  effect  upon   Fech-  p^ys^Jaf^°" 
ner,  a  German  scientist  of  philosophical  bent.      He  Law. 


12  Experimental  Psychology 

entered  with  zeal  upon  the  investigation  of  the  prob- 
lem which  Weber's  studies  had  raised,  and  for  years 
his  daily  programme  included  an  hour  or  more  of 
careful  and  accumulated  tests  of  the  validity  of 
Weber's  Law,  by  an  elaborate  method  (and  for  his 
day,  somewhat  elaborate  apparatus)  largely  of  Fech- 
ner's  own  devising.  Finding  that  the  results  he 
obtained  by  his  thousands  of  experiments  in  lifting 
weights  were  approximately  what  the  law  would 
require,  he  recast  Weber's  statement  into  a  mathe- 
matical formula  which,  in  spite  of  its  impressive  loga- 
rithmic appearance,  is  in  all  probability  not  so  near 
the  actual  truth  as  is  Weber's  own  simpler  expres- 
sion. Having  satisfied  the  mathematical  impulses 
within  him,  Fechner  next  fell  to  work  to  point  out 
the  philosophical  consequences  which  his  formula 
might  imply.  The  result  of  his  own  and  Weber's 
experiments  seemed  to  him  to  indicate  a  peculiar 
interrelation  of  brain  and  mind  —  that  the  mind  is,  in 
some  respects,  more  sluggish  than  the  brain,  and  that 
as  we  increase  the  activity  of  the  brain,  the  activity 
of  the  mind  increases  at  a  much  slower  pace.  Or,  to 
express  his  view  more  exactly  and  technically,  our 
sensations  vary  in  intensity  as  the  logarithm  of  the 
brain-action  which  corresponds  to  them.^      Because 

^  V^ith  Fechner  the  law  took  the  mathematical  form :  — 
^•=k  log?, 

0 

where  7  represents  the  intensity  of  the  sensation,  /9  the  amount  of  the 
stimulus,  b  the  threshold  intensity,  and  k  a  constant  to  be  determined 
experimentally  for  each  of  the  senses.  See  his  Elemente  der  Psycho- 
physik,  2d  ed.,  Vol.  II,  p.  13. 

It  might  be  added  that  the  essential  point  of  Fechner's  modification 


Historical  Introduction  13 

Fechner  believed  that  his  modification  of  Weber's 
Law  expressed  a  fundamental  relation  between  the 
world  of  matter  and  the  world  of  mind,  his  formula 
is  known  as  the  Psycho-physical  Law,  and  experi- 
ments in  this  line,  or  even  merely  in  verification 
of  Weber's  Law,  are  often  grouped  together  under 
the  term  "  psycho-physics." 

But  whatever  we  may  think  of  Fechner's  interpre- 
tation of  his  results,  his  robust  faith  in  experiment 
and  his  feeling  of  the  bearing  of  such  work  on 
the  fascinating  problem  of  mind  and  brain  did 
much  to  accelerate  the  movement  which  Weber  had 
inaugurated.  With  his  work  is  directly  connected 
that  of  M tiller  at  Gottingen,  whose  correspondence 
with  Fechner  over  their  common  interests  has  made 
an  attractive  little  book.  At  Miiller's  laboratory  one 
may  still  see  Fechner's  contrivances  for  his  weight 

of  Weber's  Law  is  often  attributed  to  Weber  himself,  even  by  careful 
writers.  The  statement  of  the  law,  that  for  the  sensation  to  increase 
in  arithmetical  progression  the  stimulus  must  increase  in  geometrical 
progression,  is  in  the  spirit  of  Fechner  rather  than  of  Weber.  Weber 
himself  apparently  never  went  into  the  question  of  the  mathematical 
relation  between  stimulus  and  sensation,  and  merely  expressed  the 
fact  that  in  making  comparisons  we  note  the  relative  differences  of 
things,  and  not  their  absolute  differences.  (See  his  De  Pulsu^ 
Resorptione,  Auditu,  et  Tactu,  Lips.,  1834,  p.  173;  and  also  his 
Ueber  die  Lehre  vom  Tastsinne  und  Gemeingefiihle,  1 851,  p.  105.) 
And  even  to  this  day  the  facts  seem  to  give  no  especial  warrant  for  the 
logarithmic  interpretation.  If  the  least  perceptible  difference  may  be 
psychologically  a  variable,  —  in  other  words,  since  it  is  perhaps  ever  in- 
creasing as  the  sensation  itself  increases,  —  what  is  to  prevent  our 
believing  that  stimulus  and  sensation  increase  from  threshold  to  acme 
in  practically  parallel  courses,  rather  than  that  the  sensation  increases 
at  a  slower  rate  than  the  stimulus,  as  is  so  often  stated  in  the  text-books 
as  the  obvious  meaning  of  the  psycho-physical  experiments? 


14  Experimental  Psychology 

experiments,  and  actually  still  in  use,  as  I  know,  not 
far  in  the  past.  Other  things  that  he  used  are 
treasured  at  the  Leipzig  laboratory,  in  what  the 
assistants  there  humorously  call  the  "  reliquary "  of 
the  establishment. 

Wundtand  It  is,  in  fact,  at  Leipzig  that  one  next  finds  the 
the  work  main  line  of  the  experimental  tradition.  It  was  there 
that  the  first  special  laboratory  for  psychology  was 
established  by  Professor  Wundt,  —  a  man  who  has 
for  many  years  maintained  a  preeminent  place 
among  those  interested  in  this  line  of  research. 
Like  so  many  others  who  have  contributed  to  the 
development  of  this  side  of  psychology,  Wundt  began 
as  a  physiologist,  although  even  in  his  early  writings 
one  can  detect  an  interest  beyond  the  material  pro- 
cesses involved.  But  the  philosophical  and  psycho- 
logical strain  in  the  man's  nature  became  manifest 
when  in  1874  he  published  the  first  edition  of 
his  celebrated  "  Physiological  Psychology,"  subse- 
quently many  times  rewritten  until  it  now  consists  of 
some  twelve  hundred  pages  and  more.  In  this  work 
Wundt  has  gathered  together  the  scattered  mass  of 
psychological  material,  in  large  part  from  the  experi- 
ments of  the  physiologists,  and  has  added  the  rich 
results  of  his  own  experiments  and  of  the  band  of 
workers  whom  he  has  had  associated  with  him  for 
many  years.  In  1879  he  induced  the  University 
of  Leipzig  to  set  aside  for  him  a  small  space  for 
psychological  experiments,  and  from  this  modest 
beginning  has  come  his  present  laboratory  of  most 
impressive  size  and  equipment.     Wundt's  laboratory. 


Historical  Introduction  15 

moreover,  is  the  parent  stock  from  which  a  host  of 
others  of  like  kind  have  either  directly  or  indirectly 
had  their  origin.  The  layman  can  get  an  impression 
of  its  activity  from  the  fact  that  the  Philosophische 
StudieUy  the  official  organ  of  the  laboratory,  has  just 
closed  its  career  after  completing  twenty  solid  vol- 
umes. Wundt  himself  has  shown  an  astonishing 
power  of  stimulating  the  work  and  at  the  same  time 
rendering  it  cautious  and  critical,  and  he  will  cer- 
tainly always  be  counted  one  of  the  great  figures  in 
the  history  of  modern  psychology. 

This  historical  sketch  ought  not  to  close  without  Theimpor- 
some  mention  of  the  name  of  Lotze,  whose  *'  Medi-  loS.°^ 
cinische  Psychologie  "  (1852)  is  an  important  fore- 
runner of  all  our  present  physiological  psychologies. 
The  main  current  of  the  experimental  stream  came 
less  directly  through  him  than  through  Weber  and 
Fechner ;  but  he  was  a  man  incomparably  larger  than 
either  of  them,  and  must  certainly  be  acknowledged 
as  one  of  the  great  forces  in  developing  the  work,  — 
his  mind  was  so  rich  and  frank  and  judicial  in  regard 
to  the  larger  problems  of  the  subject,  and  at  the  same 
time  so  appreciative  of  the  details  and  bearing  of 
minute  scientific  research.  It  would  be  well  if  all 
could  preserve  the  fine  balance  and  interplay  of  exact 
observation  and  large  ideas  which  Lotze  always 
showed.  If  one  were  to  attempt  to  trace  the  in- 
tellectual ancestry  of  Lotze  and  to  account  for  his 
philosophical  breadth  along  with  the  sincere  sym- 
pathy for  the  newer  methods,  this  would  undoubtedly 
lead  us  back  through  Herbart,  with  his  attempt  to 
found  a  mechanical  and  mathematical  psychology,  to 


new  work. 


1 6  Experimental  Psychology 

Leibnitz's  Leibnitz  to  whom  no  human  interest  ever  seems  to 
n^w  wnrl^^  have  been  foreign,  ranging  as  his  mind  did  through 
metaphysics,  mathematics,  law,  and  theology,  as  well 
as  through  the  minutiae  of  practical  concerns,  whether 
of  diplomacy  or  of  calculating  machines  or  of  the 
shaping  of  optical  lenses.  May  the  experimental 
work  in  psychology  always  be  worthy  of  its  great 
progenitors ! 


CHAPTER   II 

THE    GENERAL    CHARACTER    OF    PSYCHOLOGICAL 
EXPERIMENTS 

The  more  striking  influences  that  established  the  The  relation 
experimental  method  in  psychology  have  been  indi-  °o^cIh°' 
cated   in   barest   outline.     The  present  chapter  will  physiological 
be  occupied  in  showing  some  of  the  important  char-  ^^p^""^^"*^- 
acteristics  of  psychological  experiments,  and  first  of 
all  their  relation  to  physiological  investigations. 

Why  was  it  that  the  experimental  mode  of  inves-  why  were 
tigating  the  mind  came,  in  the  first  instance,  chiefly  fjl'/^'^^^f^f  ^ 
from  among  the  physiologists  rather  than  from  those  here? 
upon  whom  psychology  had  a  more  immediate  claim  ? 
The  explanation  itself  is,  I  believe,  a  psychological 
one.     The  physiologists  would  perhaps  say,  as  indeed 
many  of  them  have  said,  that  it  is  because  they  them- 
selves have  the  only  true  method  of  getting  at  the 
mental  life  scientifically  ;  that  the  only  sure  avenue  to 
the  mind  is  through  the  nervous  system,  and  that  the 
professional  psychologists   who   until   recently  have 
always  tried  to  get  at  the  facts  in  some  other  way 
were  of  course  doomed  to  failure.     One  can  experi-  a  proposed 
ment,  some  have  said,  only  on  the  nervous  system^  and  ^^p'^^^^^o'^ 
the  older  introspective  method   to   which   the   psy- 
chologists clung,  naturally  excluded  the  experimental 
procedure.     For  this  reason  experimentation  had  to 
begin  outside  the  ranks  of  the  psychologists, 
c  17 


1 8  Experimental  Psychology 

which  is  This,  howcver,  is  certainly  not  the  true  explanation. 

wrong.  Yqy^  as  a  matter  of  fact,  there  exists  no  inherent  in- 

compatibility between  introspection  and  experiment. 
Was  not  Goethe's  study  of  the  effect  of  color  upon  the 
feelings  experimental,  even  though  the  experiments 
were  indeed  very  simple  ;  and  was  it  not  also  intro- 
spective ?  He  used  his  variously  colored  glasses,  and 
directly  observed  the  inner  moods  that  they  occa- 
sioned. He  did  not  get  at  the  character  of  this  mood 
indirectly  by  first  noticing  what  effect  the  glasses 
exerted  upon  his  nervous  system.  One  may  success- 
fully perform  such  an  experiment  and  a  host  of 
others  infinitely  more  compUcated,  and  be  as  innocent 
as  a  babe  of  nervous  physiology;  he  might  believe 
that  he  thought  with  his  spleen  or  "  reins,"  and  yet 
be  competent  to  tell  that  blue  was  sobering,  while 
yellow  and  red  roused  like  a  bugle.  This  does  not 
mean  that  one  could  at  the  present  day  master 
psychology  as  a  whole  and  yet  ignore  physiology, 
for  physiology  has  made  some  of  the  most  important 
contributions  of  the  time  to  the  subject.  But  so  far 
as  the  merely  abstract  possibilities  of  the  case  are 
concerned,  experimentation  might  have  grown  up  in 
entire  independence  of  the  physiologists  —  might  have 
developed  among  those  given  to  introspection  pure 
and  simple. 

The  fact  remains,  however,  that  the  experimental 
method  actually  did  not  so  develop,  but  came  from 
the  physiologists  chiefly,  and  the  psychologists  finally 
adopted  it  because  they  found  others  getting  psycho- 
logical results  by  its  means. 

The  explanation  is  to  be  found  in  the  law  of  mental 


Character  of  Psychological  Experiments     19 

habit.  Psychology  had  for  centuries  been  intimately  influence  of 
connected  with  metaphysics,  the  same  group  of  per-  ^'^^"^abit 
sons  cultivating  both  fields.  It  was  the  most  natural 
thing  in  the  world,  therefore,  that  the  methods  which 
alone  are  appHcable  to  pure  philosophy  should  also 
be  employed  in  the  subordinate  work.  If  one  could 
study  metaphysics  with  acids  and  microscopes,  psy- 
chology would  have  had  its  laboratories  centuries 
ago.  The  physiologists,  on  the  other  hand,  were 
already  familiar  with  experimentation,  led  to  it  com- 
paratively early  because  their  problems  more  readily 
suggest  the  possibility  of  experimental  attack,  and 
also  because  the  practical  exigencies  of  sickness  and 
of  health  make  physiological  questions  more  insistent 
than  those  of  psychology.  We  must  get  exact  knowl- 
edge of  our  bodies  or  suffer  for  it,  while  we  can  be 
in  Egyptian  darkness  as  regards  our  minds,  and  yet 
have  contentment  and  long  years.  The  close  con- 
nection which  exists  between  physiology  and  chemis- 
try, one  of  the  earliest  centres  of  experimental  work, 
doubtless  also  contributed  to  the  same  result.  So 
that  when  a  physiologist  in  order  to  solve  his  own 
problems  had  to  approach  them  from  the  psycho- 
logical side,  as  he  often  must,  he  naturally  went  to 
work  by  the  methods  to  which  he  was  accustomed 
and  whose  value  had  been  so  often  forced  home. 
The  pure  psychologists,  on  the  other  hand,  were  not 
accustomed  to  such  ways,  and  therefore  had  to  see 
the  thing  done  before  they  could  recognize  its  value. 

It  must  be   confessed,   however,  that  the  experi- 
mental side  of  psychology,  whether  it  be  in  charge 


20 


Experimental  Psychology 


Suspicious 
look  of 
psycholog- 
ical exper- 
iments. 


Are  they 
not  physio- 
logical exper- 
iments 
in  disguise  ? 


The  way  to 
allay  this 
doubt. 


of  those  who  call  themselves  psychologists  or  not, 
does  to  many  persons  look  like  a  matter  of  physiology, 
pure  and  simple.  For  this  reason  it  is  not  uncommon 
to  hear  this  whole  side  of  the  subject  spoken  of  as 
**  physiological  psychology,"  as  if  it  had  to  do  very 
largely  with  brain-processes  and  nerves.  Many 
of  those  who  take  this  view  doubtless  feel  in  their 
heart  of  hearts  that  experiments  of  this  kind  must  of, 
necessity  belong  to  physiology ;  that  it  is  strictly 
impossible  to  experiment  on  the  mind  itself,  it  is 
so  coated  over  with  nerves  and  skull  and  skin,  and 
that  we  can  at  best  obtain  by  such  experiments  only 
some  facts  about  the  sense-organs  or  our  nervous 
structure  generally.  This  would  seem  to  explain 
also  the  early  precedence  of  the  physiologists  in 
the  experimental  work,  as  well  as  the  fact  that  so 
many  of  our  best  modern  psychologists  began  life 
as  physiologists  —  Lotze,  for  example,  and  Wundt 
and  James. 

Perhaps  the  best  way  to  disabuse  our  minds  of  any 
lurking  suspicion  that  psychological  experiments  are 
only  physiological  experiments  in  disguise,  is  to  select 
some  simple  instance  and  analyze  in  careful  detail  its 
character  and  meaning.  Much  depends  upon  the 
selection,  one  must  acknowledge;  for  some  of  our 
"psychological"  experiments  are  undoubtedly  noth- 
ing but  physiological,  and  no  time  should  be  lost  in 
trying  to  claim  them  for  the  mental  side.  There  are 
others,  however,  which  are  psychological —  are  experi- 
ments on  the  mind  itself,  as  distinct  from  its  nervous 
basis.  A  single  example  of  the  right  kind  will  be 
logically  sufficient  for  our  purpose. 


Fig.  I.  —  Apparatus  for  determining  the  most  rapid  succession  of 
light  sensations. 


Fig.  3. —  Reaction  experiment.     Part  of  the  apparatus  in  the 
conductor's  room. 


Character  of  Psychological  Experiments     21 

Let  us  take  a  very  humble  experiment,  then,  —  one  Examination 
that  is  as  near  the  line  between  psychology  and  physi-  f^vorabk  ex- 
ology  as  can  well  be  imagined.     If  the  problem  may  ample:  the 
be  put  in  a  very  concrete  form,  suppose  we  were  con-  ^^^^l  exper- 
structing  a  kinetoscope  and  wished  to  know  how  many 
pictures  a  second  would  have  to  be  reeled  off  to  give 
the  effect  of  absolute  and  unflickering  continuity  in 
the  moving  figures  ;  or,  to  express  it  in  a  more  general 
way,  with  what  frequency  must  successive  flashes  of 
light  come  to  the  eye  if  they  are  to  fuse  into  one 
uninterrupted  impression.     We  arrange  some  simple 
contrivance  —  we  look  through  a  revolving  disc  with 
slits  in  it,  behind  which  is  a  Hght,  as  in  Fig.  i  —  and 
gradually  increase  the  rate  at  which  the  flashes  come, 
until  a  point  is  finally  reached  where  the  distinct  and 
separate  impressions  merge  into  one  long  unbroken 
light.     This  limit  is  found  to  lie  somewhere  in  the 
neighborhood  of  forty  flashes   a  second,  but  varies 
considerably  according  to  the  conditions  of  the  ex- 
periment.^ 

Now  this  is  an  old  experiment  among  the  physiolo-  it  appears  to 
gists,  and  most  persons  would,  perhaps,  be  inclined  ^^^s^gf^ 
to  say  that  it  is  purely  a  physiological  matter.     It  is  logical; 
simply  a  case  of  after-image  or  reverberation  in  the 
eye.     When  the  flashes   come  so  close   upon   each 
other's  heels  that  the  nervous  excitation  caused  by 
one  flash  has  not  entirely  passed  away  before  the  next 
one  is  upon  it,  there  is  a  continuous  stimulation  of  the 
retina,  and  the  flashes  fuse  into  one.     The  experiment 
merely  determines  the  rapidity  of  the  retinal  process 

^  With  a  very  bright  Hght  the  Hmit  runs  as  high  as  fifty  flashes  a 
second;  with  a  very  dim  light,  as  low  as  twenty. 


22  Experimental  Psychology 

in  the  eye  (such  persons  might  say)  and  tells  us 
nothing  about  the  mind  at  all,  except,  perhaps,  that 
the  mind  is  subject  to  the  eye's  action  and  cannot 
experience  the  flashes  as  separate  when  the  nervous 
excitations  no  longer  keep  apart. 

If,  in  order  to  class  an  experiment  as  psychological, 
one  had  to  make  out  an  exclusive  claim  for  it,  such  a 
showing  as  this  would,  of  course,  require  us  to  sur- 
render the  experiment  to  the  physiologists.  But  the 
fact  is,  the  experiment  belongs  to  both  parties,  and 
however  much  the  physiologists  may  obtain  from  it, 
yet  it  begins  this  docs  not  diminish  in  the  least  what  is  there  for 
psythoiogl-  psychology.  The  experiment  certainly  does  reveal 
cai  features,  the  bchavior  of  the  nervous  coating  of  the  eye ;  but 
how  does  it  reveal  this  .?  Only  indirectly,  by  first  dis- 
closing a  peculiar  psychological  fact.  In  performing 
this  experiment  we  cannot  see  the  retina  itself  so 
as  to  say  from  direct  observation  that  the  nervous 
excitations  outlast  the  flashes  and  finally  fuse  into 
one.  What  we  do  actually  observe  is  that  the  sensation 
seems  to  become  continuous,  although  from  the  condi- 
tions of  the  experiment  we  know  that  the  light  itself 
is  being  successively  interrupted.  The  experience 
here  does  not  correspond  to  the  outer  facts,  and  from 
this  incongruity  we  infer  the  persistence  of  the  retinal 
process  during  the  interruptions  of  the  light.  The 
curious  psychic  effect,  then,  is  the  first  thing  observed, 
and  the  physiological  part  of  the  result  is  an  after- 
thought, we  might  say,  to  account  for  this  immediate 
psychological  result.  Strictly  speaking,  the  physiolo- 
gist is  here  getting  at  the  nervous  process  by  an 
indirect  and  psychological  procedure.      He  cannot 


Character  of  Psychological  Experiments     23 

observe  the  nervous  action  itself;  so,  from  an  ob- 
server's report  as  to  where  the  mental  effect  ceases 
to  correspond  exactly  to  the  outer  facts,  he  learns 
indirectly  at  what  point  the  nervous  shocks  overlap 
and  how  long  each  persists  after  the  outer  light  itself 
has  died  away. 

So  that  along  with  the  physiological  bearing  of  this  and  sheds 
experiment,  it  makes  evident  an  interesting  fact  of  J-^^Jo^JJ. 
our  mental  life.  It  shows  us  that  our  visual  impres-  mental  facts. 
sions  have  an  upper  limit  of,  say,  fifty  separate  sen- 
sations a  second,  and  that  we  cannot,  by  any  known 
contrivance,  make  them  run  with  higher  frequency. 
And  this  becomes  the  more  interesting  psychologically 
when  it  is  seen  to  offer  an  explanation  of  certain  other 
mental  facts.  Taken  in  connection  with  a  similar 
experiment  on  our  sense  of  hearing,  we  can  explain 
why  a  lapse  of  time  marked  off  by  two  flashes  seems 
shorter  than  the  same  interval  marked  off  by  two 
clicks ;  this,  in  turn,  may  explain  some  further  fact, 
and  so  the  science  of  mental  phenomena  be  furthered 
by  experiments  that  seem  at  first  to  teach  us  only  of 
our  bodies  and  to  have  no  connection  whatever  with 
the  mind. 

In  still  another  way  this  experiment  might  be  shown  The  flicker 
to  be  justly  of  interest  to  psychologists.     I  am,  of  furthel""^""^ 
course,  using  this  particular  experiment  merely  as  a  dissected, 
type  and  as  a  means  of  making  clearer  the  nature  of 
psychological-  experiments  in  general.     It  is  a  fair 
'example,  I  think,  to  assist  us  in  distinguishing  the 
psychology  of  our  experiments  from  the  physiology 
which  mingles  so  freely  with  them.     If  we  can  bring 
out  the   difference  here,  even  at  the  risk  of  mak- 


24  Experimental   Psychology 

ing  some  overdraft  on  the  reader's  attention,  it  will 
a  fortiori  be  plain  sailing  in  the  more  obviously 
psychological  region  of  memory  and  pleasure  and 
suggestion,  which  will  be  reached  in  later  chapters. 
jj  Its  results  are  From  what  was  said  a  moment  ago,  it  might  seem 
I  ex\ainedb  ^^^^  ^^  facts  that  appear  in  the  flicker  experiment 
I  the  charac-  (as  wc  may  Conveniently  call  the  one  with  the  flashes 
i^arprocess!'  ^f  Hght)  could  be  fully  explained  by  the  physical 
process  in  the  retina.  The  results,  however,  cannot 
be  entirely  understood  in  this  way,  and  on  closer 
examination  become  of  even  more  interest  to  the 
student  of  mind.  The  experiment  shows  that  when  a 
frequency  of  about  forty  flashes  a  second  is  reached 
the  flicker  usually  disappears.  It  might  seem  that  this 
limit  of  forty  flashes  a  second  was  determined  by  the 
character  of  the  nervous  process  in  the  eye,  and  that, 
as  soon  as  the  successive  excitations  began  to  over- 
lap, the  flicker  ceased.  But  if  this  were  true,  —  if  the 
overlapping  of  the  successive  processes  in  the  retina 
were  the  complete  explanation  of  the  apparent  con- 
tinuity of  the  light,  —  then,  instead  of  having  to  run 
our  flashes  up  to  a  frequency  of  forty  a  second,  four 
or  five  flashes  a  second  ought  to  suffice.  For  the  after- 
image of  each  flash  certainly  lasts  a  fifth  of  a  sec- 
ond, and  usually  much  longer.  A  boy  with  a  glowing 
brand  does  not  need  to  whirl  it  round  the  circle  in  less 
than  this  time  to  make  what  seems  a  complete  ring  of 
fire ;  the  sensation  lasts  over  the  full  interval  and  fills 
the  gap.  But  why  do  we  not  lose  the  sense  of  revo- 
lution altogether  and  see  only  a  steadily  glowing  rim } 
It  is  not  because  the  boy  cannot  keep  to  his  circle 
and,  therefore,  never  returns  exactly  to  the  point  of 


Character  of  Psychological  Experiments     25 

beginning ;  for  fasten  the  coal  to  a  revolving  wheel 

where  the  circle  is  perfect,  and  the  motion  is  still  seen,  but  are  due 

But  even  when  the  circle  is  blowing  full  round,  the  ^^^seiy  to 

,  our  power  of 

point  where  the  ember  actually  is  appears  perceptibly  discrimina- 
brighter  than  the  other  portions  of  the  circle,  and  we  *^*^" 
see  this  brightest  point  pass  round  and  round,  and  so 
feel  the  movement,  although  the  entire  ring  is  all  the 
while  aglow.  We  are  able  to  distinguish  the  brighter 
portion  from  the  dimmer,  and  see  it  move.  But  sup- 
pose the  boy  could  whirl  the  brand  so  evenly  and  so 
swiftly  that  the  coal  rounded  the  circle  before  the 
after-image  had  time  to  fade  perceptibly  dimmer  than 
the  coal  itself  —  then  the  whirling  would  appear  to 
cease,  and  we  should  see  one  steady,  moveless  ring. 
So  with  our  flashes.  It  is  not  enough  that  they  should 
come  so  close  together  that  the  second  is  there  before 
the  first  has  entirely  died  away ;  they  must  follow  so 
swiftly,  the  one  upon  the  other,  that  the  second  flash 
is  there  before  the  first  has  faded  enough  to  be  per- 
ceptibly  different  from  the  oncoming  flash.  It  is  not 
necessary  that  it  should  not  have  faded  at  all ;  some 
slight  fading  it  is  probably  impossible  to  avoid,  so  long 
as  there  is  even  the  smallest  interval  of  time  between 
the  flashes.  The  fading  must  simply  be  too  slight  for 
us  to  notice  it. 

This,  then,  is  the  additional  factor  which  helps  to 
make  this  physiological  experiment  also  a  psychologi- 
cal one.  The  results  we  get  depend  not  entirely  upon 
the  eye  but  also  upon  our  power  of  detecting  fluctua- 
tions in  our  experience.  If  our  powers  of  comparison  and  to 
were  less  fine,  then  larger  fluctuations  of  Hght  would  11^?^^'''"^^'' 
go  unnoticed  and  the  flicker  would  seem  to  die  away 


26  Experimental  Psychology 

with  far  less  than  forty  flashes  a  second ;  if  it  were 

nicer  than  it  is,  the  flashes  would  still  appear  to  come 

in  succession,  even  though  we  increased  our  rate  to 

Summary  of    8o  or  100  or  1000  a  sccoud.     A  humble  experiment 

the  psycho-     ^ikQ  this,  then,  which  at  first  seems  so  alien  to  the 

logical  mean- 
ing of  the        psychological  realm  directly  teaches  us  far  more  of 
experiment.     ^^^  bchavior  of  the  mind  than  of   the  nerves.      It 
shows  us  not  simply  that  there  is  a  rapidity  of  expe- 
rience  beyond  which  we  cannot  go,  but  that  this 
depends   upon  our  power  of   comparison,  and   that 
here,  too,  there  is  a  limit.     There  are  differences  in 
our  sensations  that  escape  us,  not  because  they  are 
too  minute  for  our  outer  sense,  but  because  they  are 
too  fine  even  for  our  "inner  sense."     We  get  indirect 
evidence  that  they  are  in  the  mind,  but  we  can  never 
directly  notice  them. 
Distinction         Where  you  class  an  experiment  depends,  therefore, 
^fchok)  •-     ^pon  what  you  are  seeking.     For  a  person  of  physio- 
caiand  logical  interest,  this  and  many  of  our  other  experi- 

experimente^  ments  are  purely  physiological;  he  heeds  only  the 
nervous  data  which  they  afford,  and  the  mental  side 
is  a  mere  lever  by  which  to  pry  out  the  hidden  bodily 
facts.  Another  person  using  the  same  apparatus  and 
performing  the  same  acts  is  watching  all  the  while 
the  working  of  the  mind,  and  for  him  the  investiga- 
tions are  psychological.  For  this  reason  psychologi- 
cal experiments,  in  their  purpose  and  results,  although 
riot  always  in  their  apparatus  and  procedure,  are  dif- 
ferent from  physiological  research.  In  making  such 
a  distinction,  however,  there  need  be  no  thought  of 
relative  value  or  superiority.  It  is  not  that  psychol- 
ogy would  be  defiled  if  found   consorting  with  the 


Character  of  Psychological  Experiments     27 

flesh;  but  only  that  there  would  be  no  logical  justifi- 
cation for  speaking  of  psychological  experiments  and 
psychological  laboratories,  if  in  reality  all  such  work 
contributed  only  to  our  knowledge  of  the  nervous 
system  and  told  us  nothing  whatever  of  the  mind. 

But  those  who  admit  that  there  really  is  a  psycho-  But  is  not 
logical  side  to  these  experiments  are  often  quite  con-  *^^r°^^. 

o  .  .  confined  to 

vinced  that  the  field  of  the  work  is  extremely  limited,  the  beggarly 
and  has  to  do  only  with  the  beggarly  elements  of  ^indT^^^^ 
mind.  This  conviction  arises  from  the  fact  that  the 
experiments  always  involve  the  use  of  the  senses. 
Whatever  the  mental  process  we  are  experimenting 
upon,  —  whether  it  be  our  sense-perception  or  mem- 
ory or  discrimination  or  our  feeling  of  pleasure, — 
the  apparatus  is  always  contrived  to  play  upon  our 
sense-organs.  Colors  are  presented  to  the  eye,  tones 
come  to  the  ear,  strips  of  paper  or  of  wood  are  offered 
to  the  touch.  Fastidious  spirits,  on  noticing  this 
characteristic  of  the  experiments,  have  often  been 
offended  by  them;  the  work  seems  to  cling  to  the 
earth  and  to  miss  the  higher  flights  of  our  mental 
life.  If  the  experimental  work  be  not  physiological 
outright,  they  hold,  it  can  at  least  never  get  above 
the  basement  levels  of  the  mind.  Since  the  appara- 
tus always  operates  upon  the  senses,  this  new  method, 
it  is  urged,  applies  only  to  sensational  processes,  to 
tasting,  smelling,  hearing,  seeing;  while  the  higher 
operations  in  which  we  are  chiefly  interested,  —  con- 
ception, imitation,  thinking,  preference,  —  all  these 
must  necessarily  lie  beyond  its  reach. 

The  subsequent  chapters  will,  I  hope,  be  the  main 


28  Experimental  Psychology 

An  iiiustra-  disproof  of  this.  But  to  illustrate  how  mistaken  the 
tion  in  reply,  yjg^  jg^  ^^^  ]^q^  easily  an  experiment  may  pass  beyond 
the  bare  process  of  perception,  even  though  the  appa- 
ratus primarily  gives  only  impressions  of  sense,  let  us 
take  an  experiment  on  our  power  to  recall  the  tem- 
poral order  in  which  a  series  of  experiences  occurred. 
Experiments  Some  simple  Contrivance  is  used  for  showing  at  the 
with  colors  saj^e  opening  of  a  box  a  series  of,  say,  eight  colors  at 
slow  and  regular  intervals,  and  thereafter,  on  com- 
pleting the  series,  any  one  of  the  colors,  haphazard,  is 
shown  a  second  time,  and  the  person  experimented 
upon  is  asked  to  tell  at  what  place  in  the  original  series 
this  special  color  appeared.  Now  if  the  colors  of  the 
entire  series  be  of  the  famiHar  sort  that  are  easily 
recognized  and  for  which  we  have  ready  names, — 
like  red,  green,  orange,  —  the  number  of  errors  which 
will  be  made  in  recalling  the  place  of  the  single  color 
in  the  series  is  much  smaller  than  when  the  colors  are 
of  rare  and  less  readily  namable  hues,  like  drab, 
buff,  and  olive, 
or  forms  And  to  show  that   the  results   here  are  not  due 

to  the  particular  colors,  we  may  use  instead  various 
black  and  white  figures.  For  the  more  familiar 
group  let  us  take  our  ordinary  English  letters,  —  K, 
S,  B,  M,  F,  P,  H,  C,  for  example,  —  and  as  a  con- 
trasting series,  difficult  to  name  and  classify,  we  may 
employ  such  nonsense  characters  as  are  shown  in 
Fig.  2,  which  are  certainly  as  striking  and  as  dis- 
tinct infer  se  as  are  our  familiar  consonants.  The 
results,  however,  are  the  same  as  before ;  the  order 
of  the  unfamiliar  forms  is  much  harder  to  remember 
than  that  of  the  letters.     In  these  experiments  the 


Character  of  Psychological  Experiments     29 

apparatus  seems  to  appeal  only  to  the  senses;  it 
offers  bare  impressions  to  the  eye.  And  yet,  in  spite 
of  this,  the  actual  result  is  to  bring  out  an  interesting 
peculiarity  of   the  mental   process  of   recalling  and 

Fig.  2.  —  Forms  for  experimenting  on  memory. 

"  placing  "  an  item  in  a  time-series.     It  tells  us  noth- 
ing of  our  sensuous  nature.     For  no  one  can  suppose  may  give 
that  the  less  famihar  colors  and  shapes  make  a  less  dle'^^e"^^  °^ 
living  impression  upon  the  eye,  and  for  this  reason  mental  traits, 
are  more  difficult  to  remember.     The  larger  number 
of  errors  here  is  rather  due  to  the  intellectual  confu- 
sion we  feel  while  the  series  is  being  given ;  we  hesi- 
tate over  their  names  and  character,  and  in  the  end 
have  but  a  vague  recollection  of  the  order  in  which 
the  series  ran.     The  retention  of  the  arrangement  of 
such  things  is,  to  put  it  otherwise,  largely  a  matter  of 
recognition  and  verbal  association ;  especially  when, 
as  in  the  present  instance,  all  logical  or  causal  con- 
nection of  the  various  members  of  the  series  is  rig- 
idly excluded. 

To  the  careless  onlooker  we  might  seem  here  to  be  why  the  ex- 
experimenting  on  one's  eyes,  but  in  reality  it  is  an  ^^e^sT^^^ 
experiment   upon   the  influence  of   recognition   and  doggedly 
verbal   associations  on   our   retention  of  a  serie?  in  ^^"^"°"^- 
time,  and  the  results  reached  are  doubtless  applicable 
to  any  series  whatever,  whether  of  sights  or  of  odors 
or  of  the  most  abstruse  conceptions  in  mathematics  or 
theology.     The  colors  and  letters  are  mere   corpora 
vilia ;  we  can  readily  get  them  into  the  laboratory ; 


30  Experimental  Psychology 

they  are  more  manageable  than  a  series  of  mathe- 
matical conceptions  would  be  for  most  of  us.  But 
the  result  is  just  as  far-reaching,  goes  as  deep  into 
the  core  of  things,  as  if  we  were  experimenting  with 
naked  abstractions  like  the  idea  of  space  of  n  dimen- 
sions, or  that  of  the  four  classic  virtues.  It  is  as  in 
an  investigation  in  physics :  an  ill-smelling  oil  lamp 
is  often  better  than  a  star.  By  confining  our  psy- 
chological experiments  to  conditions  that  are  as 
simple  and  tractable  as  possible,  there  is  doubtless  a 
loss  of  picturesqueness,  and  to  the  casual  visitor  the 
work  is  apt  to  seem  unspeakably  trivial.  There  is  a 
narrow  round  of  clicks  and  revolving  disks  and  of 
peering  through  slits  in  paper  screens,  until  it  seems 
as  if  the  experimenters  must  lack  imagination,  cling- 
ing as  they  do  to  such  insipid  stuff.  But  at  least, 
in  this  case,  the  end  justifies  the  means,  and  the 
practical  gains  from  this  apparently  wooden  and 
passionless  procedure  more  than  offset  the  loss  on 
the  aesthetic  side. 
Range  of  It  is  therefore  a  mistake  to  suppose  that  the  experi- 

psychoiogi-     niental  method  has  to  do  only  with  the  rudiments  of 

cal  experi-  -' 

ments.  psychology.     Evcn  if  the  method  were  so  confined, 

there  would  be  no  need  of  apology ;  but  we  should 
perhaps  have  to  say  that  the  glow  of  enthusiasm  with 
which  many  have  entered  upon  the  work  was  prema- 
ture. I  would  not  seem  to  magnify  the  more  recent 
tendencies.  One  may  well  appreciate  that  psychology 
was  by  no  means  a  failure  before  it  reached  the  ex- 
perimental stage,  and  that  some  of  our  most  interest- 
ing mental  processes  are  exceedingly  difficult  to  deal 
with  in  the  laboratory.     But  admitting  all  this,  it  is 


Character  of  Psychological  Experiments     31 

nevertheless  erroneous  to  hold,  as  many  do,  that  there 
is  some  fundamental  and  inherent  limitation  in  the 
method  itself.  So  far  as  one  can  now  see,  the  method 
is  equal  to  almost  anything ;  the  rest  is  a  mere  ques- 
tion of  genius  in  the  psychologists  themselves.  What 
is  needed  is  wit  to  adapt  the  method  to  the  problems 
in  hand.  But  already  at  the  very  beginning  of  the 
work  there  is  hardly  any  great  class  of  mental  phe- 
nomena that  has  not  been  experimentally  approached 
in  some  way.  The  range  of  these  studies  has  so 
rapidly  enlarged  that  the  enumeration  of  the  varied 
contributions  would  be  as  long  and  monotonous  as 
Homer's  catalogue  of  the  ships.  The  subsequent 
chapters  will  aim  to  give  an  impression  of  their  scope 
and  purport  in  some  of  the  more  important  directions. 

And  now  a  closing  word  as  to  the  place  of  experi-  Their  place 
ments  among  the  general  resources  of  psychology.  aVawho^e'^^ 
Although  the  experimental  trend  came  in  historically 
from  the  physiological  side  and  with  some  show  of 
hostility  toward  the  older  introspective  method,  we 
have  seen  that  there  is  no  essential  antagonism  be- 
tween the  experimental  method  and  introspection. 
Introspection  is  really  at  the  bottom  of  every  method 
in  psychology,  and  without  the  initial  data  which 
self-observation  affords  none  of  the  so-called  "  objec- 
tive "  methods  in  psychology  could  make  so  much  as 
a  start.  So  that  we  must  not  become  partisans  and 
cry  up  the  new  as  if  it  could  utterly  supplant  the  old. 
For  this  reason  it  seems  ill-advised  to  attempt  an 
absolute  separation  of  experimental  psychology  from 
psychology  based  upon  other  methods,  as  if  the  ex- 
perimental studies  should  make  up  a  science  of  their 


32  Experimental  Psychology 

own  —  something  apart,  and  not  to  be  contaminated 
with  the  results  of  mere  observation.  In  discussing 
the  various  questions  upon  which  experimentation 
casts  an  important  light,  there  will  consequently  be 
no  attempt  to  look  at  these  problems  exclusively  in 
this  light.  If  the  experimental  side  is  emphasized, 
it  is  not  in  a  party  spirit ;  there  is  no  question  of 
principle  involved,  and  there  is  the  freest  admission 
of  the  value  of  other  modes  of  attack. 


CHAPTER   III 

THE  POSSIBILITY   OF  MENTAL  MEASUREMENTS 

The  subject  of  this  chapter  plunges  one  into  the  The  problem 
heart  of  the  experimental  work.      To  many  the  sue-  ^gnffs^^'^^' 
cess  or  failure  of  the  new  departure  in  psychology  momentous 
seems  to  hinge  on  the  question  whether  mental  facts  wicar^°' 
will  permit  of  being  measured.     If  these  can  be  meas-  method, 
ured,  they  would  say,  then  and  only  then  is  it  possi- 
ble to  have  a  scientific  study  of  the  mind.     It  is  not 
enough  that  we  should  be  able  to  perform  experi- 
ments ;   our  experiments  must  be  capable  of  giving 
us  results  that  are  quantitative.      In  the  old  school 
they  were  satisfied  with  determining  the  qualities  and 
kinds  of  mental  facts,  but  now  we  must  discover  their 
nicer  mathematical  relations.     Psychology  must  have 
something  comparable  to  the  exact  weights  and  vol- 
umes and  durations  with  which  the  physical  sciences 
deal  and  to  which  they  owe  their  great  success.     It 
is  held  that  unless  we  can  make  measurements  in  the 
mental  realm  similar  to  the  quantitative  researches  in 
chemistry  and  physics,  we  are   no  better  than  our 
fathers,  and  the  modern  turn  in  psychology  brings  in 
no  essentially  new  resources  by  which  to  lay  bare  the 
structure  of  the  mind.     The  question  of  quantitative 
results  in  psychology  is  therefore  a  living  one ;    it 
touches  the  subject  in  the  quick.     And  while  some 
D  33 


34 


Experimental  Psychology 


Psychic 
measure- 
ment is 
declared  im- 
possible. 


Common- 
sense  diffi- 
culties. 


of  US  may  think  that  those  who  regard  this  issue  as 
a  matter  of  scientific  life  and  death  are  taking  it  per- 
haps too  seriously ;  yet,  short  of  life  and  death,  it  is  as 
important  a  problem  of  method  as  the  experimenters 
have  to  confront.  Experiments  can  certainly  proceed 
even  if  exact  measurements  should  prove  impossible, 
but  it  would  be  a  halting  progress  and  a  great  dis- 
appointment to  those  who  have  heralded  the  new 
methods  as  the  beginning  of  nicer  and  more  fruitful 
work  in  this  difficult  field. 

The  question  is  one  upon  which  there  are  honest 
differences  of  opinion.  No  less  a  person  than  Kant, 
for  instance,  believed  that  mental  measurements  were 
an  a  priori  impossibility.  Those  of  opposite  view 
may  speak  patronizingly  of  him  as  of  one  who  lived 
under  the  old  dispensation  before  our  psychological 
laboratories  had  shown  what  was  the  range  of  pos- 
sibilities in  the  case.  But  we  cannot  so  readily  ex- 
plain similar  views  which  persist  to-day  even  amongst 
those  who  are  familiar  with  all  the  details  of  the 
experimental  work.  Some  who  are  entirely  at  home 
in  the  laboratory  methods  are  still  in  perfect  agree- 
ment with  the  Kantian  doctrine,  and  when  it  comes 
to  the  question  whether  there  are  any  strictly  mental 
measurements  in  our  modern  researches,  they  answer 
with  an  unequivocal  No. 

Our  common-sense  prejudice,  I  think,  is  apt  to 
make  us  sympathize  with  this  negative  side  of  the 
matter.  Probably  most  of  us  have  an  instinctive 
conviction  that  we  can  measure  only  the  things  of 
the  physical  world ;  we  can  measure  land  or  indi- 
cate degrees  of  temperature,  and  we  understand  what 


i 


Possibility  of  Mental  Measurements       35 

is  meant  by  the  weight  of  the  human  brain.  But 
what  should  we  mean  by  the  literal  metes  and  bounds 
of  a  man's  mental  life,  or  by  a  quantitative  estimate 
of  one's  spiritual  acts  ?  The  use  of  mathematical  lan- 
guage in  regard  to  such  things  has  a  humorous  effect, 
as  when  Plato  tells  us  in  the  "  Republic  "  that  the  just 
ruler  is  found  by  elaborate  computation  to  be  exactly 
729  times  happier  than  the  tyrant.  The  facts  them- 
selves seem  too  vague  and  elusive  for  such  treatment. 
Moreover,  measurement  seems  to  imply  the  applica- 
tion of  the  measuring  apparatus  to  the  object.  But 
where,  as  in  the  present  case,  the  facts  to  be  meas- 
ured and  our  instruments  of  precision  lie  in  totally 
different  realms,  what  result  can  we  ever  hope  to 
attain  ?  In  some  such  way  we  might  express  the 
doubt  that  arises  at  the  bare  mention  of  the  proposal. 

There  is,  however,  a  metaphysical  objection  that  Metaphys- 
attacks  the  possibility  of  measurement  in  a  much  Jp^^°^J^^" 
subtler  and  more  radical  way.  The  common-sense 
objection  is  of  a  practical  nature  —  the  practical  diffi- 
culty of  bringing  our  measuring  rod  and  our  psycho- 
logical object  into  the  same  sphere  and  of  applying 
the  one  to  the  other.  But  the  more  philosophical 
objection  is,  that  even  if  we  could  carry  our  instru- 
ments into  the  mental  realm,  we  should  find  nothing 
there  that  could  possibly  be  measured.  The  very 
nature  of  mental  facts  is  such  that  they  are  not  sub- 
ject to  measurement.  The  difficulty  now  is  a  logical 
rather  than  a  practical  one ;  it  is  asserted  that  there 
is  an  inherent  absurdity  in  the  very  thought  of  meas- 
uring mental  things  ;  that  between  the  notion  of  mind 
and  the  notion  of  measurement  there  is,  to  use  Berke- 


^6  Experimental  Psychology 

ley's  phrase,  a  manifest  repugnancy :  the  one  concep- 
tion cannot  tolerate  the  other.  Measurement  always 
implies  that  the  thing  to  be  measured  is  quantitative 
and  may  be  stated  in  numerical  terms  and  manipu- 
lated mathematically.  The  facts  of  mind,  however, 
it  is  maintained,  exclude  any  such  idea ;  they  are  not 
quantitative  and  are  therefore  not  measurable.  Math- 
ematics is  inapplicable  to  the  mental  life,  and  for  this 
reason  psychology  can  never  hope  to  attain  the  status 
of  a  science. 

This,  in  brief,  is  the  a  priori  objection  to  all  meas- 
urement in  the  mental  field.  It  springs  perhaps 
ultimately  from  a  definition  of  the  soul,  as  given  in 
metaphysics.  The  soul  is  a  simple  substance,  the 
metaphysics  of  mind  has  often  taught  —  a  simple  sub- 
stance without  parts  and  without  extension.  Such  a 
description  readily  suggests  that  the  soul  has  no 
quantum,  and  that  measurement  in  its  case  is  mean- 
ingless and  impossible. 
Need  of  The  most  telling  refutation  of  such  an  argument  is 

LTtatices^of  ^^  ^^  ^^^  ^^^^S  ^^^*  ^^  alleged  to  be  impossible  —  to 
measure-  prove  that  you  can  walk  by  walking.  And  this  is 
the  answer  on  which  the  experimenters,  in  the  main, 
have  relied.  They  are  inclined  to  show  their  method 
and  its  results  and  to  invite  one  to  draw  his  own  con- 
clusions. And  we  may  follow  them  to  the  extent,  at 
least,  of  postponing  the  consideration  of  the  various 
theoretical  difficulties  until  we  have  the  character  of 
the  experimental  work  more  clearly  before  us.  We 
had  better  take  up  in  some  detail  a  number  of  charac- 
teristic experiments  of  the  less  complicated  sort,  and 
then,  by  a  careful   analysis,  try  to   decide  whether 


ment. 


Possibility  of  Mental  Measurements       37 

they  actually  escape  the  grave  objections  that  can  be 
raised  against  the  quantitative  work. 

It  is  perhaps  unnecessary  to  warn  the  reader  that  a  warning 
experiments  in  this  field  are  less  ambitious  than  some  ^  ^°  ^^^^^ 

^  aim. 

may  have  been  led  to  expect.  There  is  no  thought 
of  measuring  one's  mind  as  a  whole,  nor  of  determin- 
ing its  general  range  and  efficiency.  The  expression 
"  mental  measurement "  might  suggest  such  a  thought 
to  the  unwary.  But  if  for  this  reason  it  seems  objec- 
tionable, it  is  at  least  an  improvement  on  an  older  term 
which  at  one  time  bade  fair  to  be  the  designation  for 
all  this  kind  of  psychological  work  —  the  term  'i-psy- 
chometry."  This  word  has  fallen  into  disuse  because 
it  almost  justified  the  belief  that  the  laboratories  pre- 
tended to  some  sort  of  mental  caliper  by  which  to 
determine  the  gauge  of  any  given  mind.  An  addi- 
tional reason  for  discarding  it  was  that  the  theoso- 
phists  adopted  it  to  denote  perhaps  no  one  could  say 
what,  except  that  it  was  something  totally  different 
from  what  the  psychologists  ever  intended.  In  men- 
tal measurements,  therefore,  there  is  no  pretence  of 
taking  the  mind's  measure  as  a  whole,  nor  is  there 
usually  any  immediate  intention  of  testing  even  some 
special  faculty  or  capacity  of  the  individual.  What 
is  aimed  at  is  the  measurement  of  some  limited  event 
in  consciousness,  such  as  a  particular  perception  or 
feeling.  The  experiments  are  addressed,  of  course, 
not  to  the  weight  or  size  of  such  phenomena,  but  usu- 
ally to  their  duration  and  intensity. 

We  might  first  consider,  then,  some  experiments 
which  aim  to  measure  the  time  of  psychic  phenomena. 


38 


Experimental  Psychology 


I.  Examples 
of  time- 
measure- 
ment. 


Apparatus 
and  method. 


Without  any  apparatus  at  all  we  should  be  able  to 
say  that  the  duration  of  our  mental  processes  varied 
enormously  ;  that  to-day  we  can  go  through  a  mental 
operation  in  a  few  moments  that  once  would  have 
required  hours.  And  if  we  were  to  attempt  to  meas- 
ure accurately  by  instruments  the  time  required  for 
some  of  our  acts,  we  should  have  to  use  nothing  short 
of  an  eight-day  clock.  The  actual  laboratory  work  in 
time-measurement,  however,  has  been  narrowed  down 
to  determining,  not  the  time  in  general  that  is  occu- 
pied by  some  mental  action,  but  rather  the  shortest 
possible  time  in  which  a  particular  operation,  like  dis- 
crimination or  choice  or  association  or  recognition, 
can  be  performed  under  the  simplest  and  most  favor- 
able circumstances.  The  experimental  results  here 
are  something  like  speed-  or  racing-records,  made 
under  the  best  conditions  of  track  and  training.  A 
delicate  chronograph  or  chronoscope  is  used,  which 
marks  the  time  in  thousandths  of  a  second. 

The  method  generally  employed  is  that  of  a  "  re- 
action "  experiment,  already  alluded  to  in  speaking  of 
the  astronomical  observatories  and  the  psychological 
experiments  on  personal  equation.  Some  suitable 
object  is  suddenly  disclosed  to  the  attentive  observer, 
he  goes  through  a  prearranged  mental  operation,  and 
immediately  at  its  completion  moves  an  electric  key 
on  which  his  finger  has  been  resting.  The  chro- 
nometer records  the  time  between  the  display  of  the 
object  (at  which  time,  approximately,  the  mental  pro- 
cess began)  and  the  subject's  movement  which  signals 
the  close  of  the  mental  act.  The  time  recorded,  after 
making  certain  necessary  corrections  to  be  considered 


b 


Fig.  4.  —  Reaction  experiment.    The  arrangement  in  the  subject's  room. 
In  actual  experiment  the  room  would  be  darkened. 


Fig.  9. 


■Apparatus  for  crossing  the  threshold  of  sound.     In  actual  use 
the  telephone  would  be  in  a  distant  room. 


Possibility  of  Mental   Measurements       29 

directly,  is  assumed  to  represent  the  duration  of  the 
mental  operation  with  which  the  experiment  was  con- 
cerned. 

To  take  a  definite  and  concrete  case,  suppose  we  Reaction  to 
wish  to  ascertain  the  time  required  for  a  person  to  ^^^^** 
become  conscious  of  a  light  suddenly  flashed  into  -his 
eyes  and  to  give  a  muscular  impulse  to  his  hand  as 
a  sign  that  the  light  was  seen.  An  experimenter  with 
his  electric  chronometer  and  connections,  as  shown  in 
Fig.  3,  is  able  to  give  a  flash  of  light  in  a  distant  room 
and  to  record  exactly  the  time  when  the  flash  was 
given.  The  person  experimented  upon,  sitting  ready 
and  expectant  (Fig.  4),  moves  an  electric  key,  and  in- 
stantly this  "  reaction  "  is  recorded  on  the  chronometer 
in  the  experimenter's  room.  The  time  between  flash 
and  movement  would  in  the  present  case  perhaps 
amount  to  from  180  to  280  thousandths  of  a  second, 
according  to  the  person's  method  of  reacting. 

Now  from  such  a  record  as  this,  supposing  it  to  have  Results. 
been  checked  and  corrected  by  many  hundred  similar 
experiments,  what  do  we  learn  as  to  the  time  occupied 
by  the  mental  process  of  receiving  and  responding 
to  the  flash  ?  First  of  all,  we  know  that  the  mental 
operation  has  occupied  by  no  means  all  of  these  180  to  Necessary 
280  thousandths  of  a  second.  A  considerable  part 
of  the  time  has  been  used  in  the  purely  mechanical 
process  of  transmitting  the  message  to  the  brain  and 
of  conveying  the  message  back  from  brain  to  hand. 
It  takes  some  time  for  the  Hght  to  start  a  nervous 
excitation  in  the  eye ;  it  takes  additional  time  for  this 
excitation  to  pass  along  the  optic  nerve  to  the  brain 
and  up  through  the  brain  to  its  gray  surface.     Not 


40  Experimental  Psychology 

until  this  region  —  the  cerebral  cortex  —  has  been 
reached  is  there  any  consciousness  of  the  light.  So 
that  if  our  time-record  were  confined  to  the  purely 
psychic  and  cortical  part  of  the  operation,  it  should 
begin,  not  with  the  external  flash  of  light,  but  with 
the  arrival  of  the  message  in  the  central  office,  when 
it  reaches  the  gray  matter  of  the  hemispheres.  And 
likewise  with  the  transmission  of  the  reply.  If  we 
could  exactly  mark  the  time  of  the  mental  process, 
our  record  would  close  at  the  instant  the  message 
had  become  formulated  in  the  subject's  mind,  and 
the  corresponding  operation  had  taken  place  in  the 
cortex.  But  instead,  our  clock  keeps  on  and  includes 
the  time  while  the  answer  is  coming  from  the  motor 
region  of  the  brain,  down  through  the  deeper  cere- 
bral centres  and  the  spinal  cord  and  along  the  motor 
nerve  out  to  the  muscles  that  finally  cause  the  finger 
to  respond.  The  chronometer  thus  records  a  con- 
siderable amount  of  dead  time  —  of  time  not  required 
to  begin  and  end  the  mental  and  cortical  part  of  the 
work  at  all ;  and  to  get  at  the  time  of  the  mental 
operation,  this  dead  time  would  of  course  have  to  be 
deducted.  ^ 

1  In  this  chapter  the  timing  of  mental  processes  is  illustrated  only 
by  the  reaction  method.  There  is  at  least  one  other  way,  however, 
that  avoids  some  of  the  theoretical  difficulty  which  the  reaction  method 
undoubtedly  has.  The  flicker  experiment  of  the  preceding  chapter, 
for  example,  might  serve  as  an  instance  of  timing  our  mental  acts  by 
a  non-reaction  method.  It  shows  that  the  least  noticeable  fluctua- 
tions in  vision  can  occur  with  a  frequency  of  20  to  50  a  second,  and 
therefore  that  each  separate  process  occupies  between  50  and  20  thou- 
sandths of  a  second.  The  view  proposed  in  the  text  that  there  is  here 
a  kind  of  rudimentary  discrimination  of  the  successive  intensities  is  to 


Possibility  of  Mental   Measurements       41 

Such  measurement  is  of  value  not  alone  from  its  a  foundation 
inherent  interest,  but  as  a  starting-point  for  further  JJ'q/^'^^^^'^ 
work,  in  approximating  the  time  of  more  complicated 
processes.  One  may  next  investigate  the  time  re- 
quired not  merely  to  receive  the  mental  impression 
of  light  in  general,  but  to  recognize  the  kind  of  light,  Recognition 
whether,  for  instance,  it  be  red  or  blue  or  something  ^^""^* 
else.  The  general  character  of  the  experiment  would 
be  the  same  as  before,  except  that  instead  of  repeating 
at  each  trial  the  self -same  kind  of  light,  the  subject 
now  never  knows  beforehand  what  the  color  of  the 
light  will  be.  At  first  he  will  probably  be  flurried, 
and  his  reaction  will  not  be  exactly  according  to  pro- 
gramme; but  in  time  his  nervousness  subsides  and 
he  settles  down  to  regular  responses  in  which  we  can 
be  reasonably  certain  that  his  reaction  is  not  made 
until  after  he  has  discerned  the  color  of  the  light, 
whereas  at  the  beginning  he  may  have  reacted  at  the 
bare  coming  of  the  flash  regardless  of  its  hue.  The 
time  between  light  and  reaction  will  under  these  cir- 
cumstances lengthen  perhaps  to  310  thousandths  of  a 

some  extent  confirmed  by  the  fact  that  these  numbers  (20-50<^)  are  not 
far  from  those  obtained  for  discrimination  or  recognition  (the  two  are 
not  very  different)  by  the  reaction  method.  Titchener,  for  instance,  work- 
ing by  the  reaction  method  {Philosophische  Studien,  Vol.  VIII,  p.  138)^ 
found  that  the  recognition  of  a  color  takes  place  in  about  30«^.  Cattell 
calculates  from  his  reaction  experiments  that  the  discrimination  of  white 
light,  when  the  kind  of  light  had  not  to  be  discriminated,  required  for 
Subject  B,  300-;  for  Subject  C,  50*^  {Philosophische  Studien,  Vol.  Ill, 
p.  455).  In  the  flicker  experiment  the  interval  is  obtained  without 
the  need  of  computing  what  I  have  called  the  "  dead  "  time,  so  that 
this  particular  difficulty  is  avoided.  But  the  method  is  not  so  widely 
applicable  as  the  reaction  method  has  been  found  to  be,  and  is  there- 
fore on  the  whole  less  attractive. 


time. 


42  Experimental  Psychology 

second,  as  against  280  with  the  same  observer  where 
no  recognition  of  the  colors  had  to  be  performed.  It 
is  fair  to  assume  that  the  increase  of  the  interval  — 
the  difference  between  280  and  310  thousandths  — 
is  the  time  required  for  this  additional  act;  for  in 
other  respects  the  experiment  has  remained  un- 
changed. 1 
Association  By  a  similar  modification  of  the  reaction  experiment, 
the  details  of  which  it  is  not  necessary  to  describe,  it 
is  found  that  for  an  association  of  distinct  ideas  to  arise 
in  the  mind  (for  '*  ship  "  to  remind  us  of  "  sea,"  for 
example,  or  for  "north  "  to  recall  "south")  the  reac- 
tion-time lengthens  to  a  period  ranging  from  1.009  to 
1. 1 54  seconds  in  certain  observers.  It  is  interesting 
to  note  that  if  the  person  upon  whom  we  are  experi- 
menting is  instructed  beforehand  to  confine  his  asso- 
ciations to  certain  definite  directions,  the  process 
takes  less  time  than  when  he  is  given  perfect  free- 
dom to  let  in  associations  riotously  from  any  point  of 
the  compass.  If,  for  instance,  he  be  required  to  call 
up  some  association  that  stands  to  the  idea  given  him, 
in  the  relation  of  part  to  whole  and  we  then  give  him 
the  word  "bear,"  he  will  get  a  definite  association 
such  as  "skin,"  or  "paw,"  in  a  shorter  time  than  if 
he  had  the  option  of  calling  up  an  association  of  any 
kind  whatever,  like  "mammal,"  "fur,"  "  North  Pole," 
or  "honey."  The  very  number  of  things  coming,  in 
the  latter  case,  seems  to  choke  the  avenues  of  the 

1  For  concreteness*  sake  I  have  taken  the  numbers  here  from  the 
experiments  on  Professor  Titchener,  as  reported  by  himself.  They  are 
fairly  typical.  See  his  "Zur  Chronometrie  des  Erkennungsactes," 
Philosophische  Studien,  Vol.  VIII,  p.  138. 


Possibility  of  Mental  Measurements       43 

mind ;  the  crowding  ideas  produce  an  instant's  dead- 
lock and  confusion,  whereas  if  nine-tenths  of  them 
were  excluded  at  the  outset,  some  one  idea  would 
rush  through  the  gates  the  sooner.  It  seems  to  be 
an  instance,  on  a  small  scale,  of  what  appears  in 
common  life  where  men  of  limited  view  —  "men  of 
one  idea" — are  so  often  of  great  practical  efficiency, 
while  those  of  wider  mental  range  can  perform  noth- 
ing of  importance  without  first  rejecting  a  host  of 
suggested  lines  of  action.  If  quickness  were  the  one 
thing  needful,  rigid  habit  without  options  would  be 
our  best  equipment ;  for  freedom  of  selection  always 
means  an  initial  hesitation  and  loss  of  time. 

As  an   example  of   experiments  dealing  with  the  11.  The 
intensity  of  a  mental  fact,  we  might  select  the  phe-  JJJgnt^^" 
nomenon  of  color  contrast.    It  is  well  known  that  any  psychic  in- 
color  tends  to  cast  a  complementary  hue  over  sur-  ?^^in'coior 
rounding    objects    that    are   not   themselves    highly  contrast. 
colored.     Shadows  near  bright  colors  take  on  these 
complementary   tints   in   a   striking   way,  since   the 
shadow  is   subdued   and   more   neutral  in  tone  and 
therefore   offers  little  color  of  its  own  to  resist  the 
contrast   influence.     For    this   reason  shadows  near 
green  foliage   or  on  the  green  sea  or  on  brown   or 
golden  fields  show  a  distinctly  purple  or  violet  hue, 
and  in  some  of  our  modern  works  of  art  these  con- 
trast purples  have  been  brought  out  in  such  regal 
splendor  that  little  else  can  be  seen. 

Now  contrast  of  this  sort  is  a  psychological  effect 
(although  doubtless  mediated  by  physiological  condi- 
tions), and,  in  a  way,  it  can  be  measured.  For  experi- 
mental purposes  it  is  more  convenient  to  reproduce 


44 


Experimental  Psychology 


the  phenomenon  on  a  small  and  unimposing  scale 
with  a  revolving  circular  disk  of  paper  arranged  as  is 
shown  in  Fig.  5,  where  there  is  an  inner  and  an  outer 
zone  of  some  bright  color,  —  say  green,  —  and  a  mid- 
dle portion  composed  of  alternate  black  and  white 
segments.  When  the  disk  is  rapidly  revolved  by  an 
electric  motor,  these  colorless  segments  fuse  into  a 
single  uniform  ring ;  but  instead  of  this  middle  band 
appearing  a  neutral  gray  (as  a  mixture  of  black  and 


Fig.  5.  —  Disk  for  the  produc- 
tion of  color  contrast.  If 
the  two  cross-hatched  zones 
be  of  bright  green,  the  zone 
made  up  of  black  and  white 
will  upon  rapid  rotation  take 
on  (by  contrast)  a  reddish 
hue. 


Fig.  6.— Disk  for  the  meas- 
urement of  the  contrast 
effect  in  Fig.  5.  The  cross- 
hatched  segment  represents 
red,  which  may  be  varied  in 
amount  until  the  middle  zone 
on  rapid  rotation  matches 
the  middle  zone  of  Fig.  5. 


white  should),  it  is  seen  to  be  decidedly  tinged  with 
red.  If  we  cover  the  two  green  portions  of  the  disk, 
the  zone  between  them  at  once  becomes  colorless, 
showing  that  the  reddish  tint  is  a  contrast  effect  due 
solely  to  the  neighboring  green.  To  measure  the 
amount  of  this  contrast  hue,  we  set  beside  it  another 
revolving  disk  which  Hkewise  has  three  concentric 
zones  (Fig.  6)  but  whose  inner  and  outer  rings  are 
colorless,  while  in  the  ring  between  them  there  is  a 
variable  sector  of  red  which  permits  us  to  change  at 
will  the  proportion  of  red  and  gray  in  this  middle  zone. 
By  this  second  apparatus  we  can  thus  produce  a  series 


I 


Possibility  of  Mental   Measurements       45 

of  grayish  reds  until  we  have  approximately  matched 
the  reddish  tone  that  appeared  on  our  first  disk  by 
contrast.  It  is  now  found  that  from  thirty  to  fifty 
degrees  of  the  red  sector  must  be  exposed  in  the  gray- 
ish ring  of  the  measuring  disk  to  produce  an  effect 
equal  to  the  mere  proximity  of  the  green.  Experi- 
ment shows  that  the  number  of  degrees  required  for 
a  match  differs  according  to  the  person,  the  kind  of 
green  we  use,  the  shade  of  gray,  and  various  other 
conditions  of  the  trial.  It  is  in  any  case  but  an 
approximation,  and  I  shall  indicate  later  with  what 
caution  inferences  should  be  drawn  from  these  and 
similar  results. 

A  single  additional  example  of  measurement  will  iii.  Meas- 
suffice.    We  all  know  that  the  bhnd  show  an  astonish-  ^^^"^^"^  ^^ 

space  dis- 

ing  cleverness  in  using  their  sense  of  touch.     Does  crimination, 
their  superiority  to  us  lie  in  the  fact,  as  some  have 
thought,  that  their  finger-tips  have  developed  a  much  e.g.  in  the 
finer  nervous  structure  than  ours  }     If  so,  experiment  ^^^"^* 
ought  to  show  that  impressions  so  close  together  as 
to  be  quite  indistinguishable  for  us  were  still  separate 
enough  for  their  finer  sense.      We  should  make  care- 
ful experiments  on  the  blind  and  on  normal  persons 
of  like  age  and  intelligence  and  of   similar  manual 
employments,  to  find  what  is  the  least  space  difference 
that  each  class  can  discriminate. 

By  measuring  the  spatial  nicety  of  their  skin  with 
compass-points,  —  that  is,  by  finding  how  far  apart 
the  two  compass  points  must  be  for  the  subject  to  feel 
them  as  two  and  not  as  one,  —  we  learn  that  in  chil- 
dren (whose  sensibility  in  this  respect  is  in  general 
finer  than  that  of  adults),  it  is  necessary  to  open  our 


46  Experimental  Psychology- 

compasses  a  little  more  or  less  than  one  millimetre 
(about  one  twenty-fifth  of  an  inch)  before  the  two 
points  seem  to  lie  on  distinctly  different  places  on  the 
skin,  —  a  result  practically  the  same  as  that  which  we 
get  by  similar  experiments  on  children  who  can  see.^ 
There  is,  perhaps,  a  slight  advantage  on  the  side  of 
the  blind,  but  nothing  sufficient  to  account  for  their 
deftness  in  using  their  sense  of  touch,  as  in  reading. 
The  tactile  superiority  of  the  blind  is  not  due,  then, 
to  some  extraordinary  development  of  the  organ  of 
touch.  They  do  not  obtain  through  their  fingers  in- 
conceivably finer  gradations  of  impression  than  we  do, 
but  by  long  practice  and  attention  they  have  learned 
to  see  a  world  of  meaning  in  the  very  impressions 
which  we  receive  as  tame  and  unsuggestive,  distracted 
as  we  are  by  the  more  interesting  sensations  of  light 
and  color.  The  blind  have  little  if  any  greater  nicety 
of  the  sense  itself,  but  infinitely  greater  readiness  in 
understanding  the  meaning  of  what  the  sense  reports. 

iThis  result,  already  indicated  by  earlier  experiments  (cf.  the 
authorities  in  Heller, "  Studien  zur  Blinden-Psychologie,"  Philosophische 
Studien,  Vol.  XI,  p.  226),  has  been  confirmed  by  the  experiments  of 
some  of  my  students,  courteously  aided  by  Dr.  Wilkinson,  the  super- 
intendent of  the  California  State  Institution  for  the  Deaf  and  Blind. 
Miss  Katharine  Bunnell,  working  with  five  blind  subjects  and  five 
normal  persons,  and  Miss  Agnes  Stowell,  with  a  separate  group  of 
subjects  (eight  blind  and  eight  normal),  find  the  thresholds  to  be  but 
slightly  in  favor  of  the  blind. 

As  regards  the  least  pressure  that  can  be  perceived  at  all  —  a  ques- 
tion to  which  experimenters  on  the  blind  have  given  far  less  attention 
—  there  appears  to  be  a  decided  advantage  for  the  blind,  according  to 
some  preliminary  experiments  by  one  of  my  students,  Mr.  Otto  Schulze. 
As  to  the  meaning  of  this,  I  should  prefer  to  reserve  judgment,  how- 
ever, until  the  results  are  quite  beyond  doubt. 


Possibility  of  Mental   Measurements       47 

It  is  as  in  the  case  of  language,  where  the  same 
sounds  give  such  different  results  according  as  they 
are  or  are  not  of  our  mother  tongue.  In  listening  to  a 
language,  the  native  and  the  stranger  are  on  an  equal 
footing  so  far  as  the  mere  sense  of  hearing  is  con- 
cerned ;  and  yet,  even  when  the  stranger  knows  the 
tongue  quite  well,  he  must  stand  nearer  a  speaker 
in  order  to  understand  him.  The  native  can  disen- 
tangle the  snarl  of  sounds,  can  catch  the  signifi- 
cance of  slight  differences  which  to  the  other  are  as 
good  as  lost.  Our  experiments  in  measurement  give 
some  hint,  then,  not  only  of  the  general  character  of 
quantitative  work  in  psychology,  but  also  of  the  use 
to  which  the  results  can  be  put  in  clearing  up  more 
compHcated  mental  problems. 

With  these   instances  of   laboratory  measurement  Return  to  the 

we  may  return  to  the  question  raised  at  the  beginning  °J"'§^J1^^ 

of  the  chapter.     Can  such  experiments  justly  claim  such  exper- 

to  measure  mental  phenomena,  or  must  we,  in  spite  of  ™^"^^  ^^^^^y 

^  ...  '  r  measure 

them,  reaffirm  that  quantitative  notions  are  absolutely  mental  pro- 
aHen  to  the  mental  realm  ?     We  are  now  in  posses-  ^^^^^^  ^ 
sion  of  the  main  facts  of  the  case,  and  must  next  try 
to  render  some  decision  upon  this  question.     Here  And,  first, 
the  hard  work  fairly  begins,  I  fear,  and  the  reader  ^VcWc^"^ 
must  prepare  for  a  somewhat  trying  review  of  the  quantity  to 
various  difficulties  in  this  subtle  but  important  prob- 
lem.    After  all,  a  closer  examination  of  the  theoreti- 
cal objections  to  the  experiments  in  measurement  is 
the  best  means  of  seeing  what  the  experiments  them- 
selves really  are. 
The   hottest   of   the  dispute   has   been   over   the 


measure  ? 


48 


Experimental  Psychology 


Review  of 
four  kinds  of 
quality 
available : 

I.  Intensity. 


The  claim 
that  every 
mental  phe- 
nomenon is 
one  and 
indivisible. 


But  so  is  a 
tree,  strictly 
speaking. 


intensity  of  psychic  processes,  and  more  particularly 
over  the  intensity  of  sensations.  For  no  one,  so  far 
as  I  know,  has  ever  seriously  claimed  that  there  is 
any  intensive  character  to  the  mental  activity  whereby 
things  are  held  in  relation  and  bound  into  wholes,  — 
as,  for  example,  the  mental  act  of  connecting  two 
ideas  logically,  as  subject  and  predicate  in  a  judg- 
ment. So  that  intensity  is  to  be  found,  if  at  all,  in 
sensations  and  feeUngs  —  in  the  materia  prima  of 
consciousness,  rather  than  in  its  "form." 

Fechner's  famous  elaboration  of  Weber's  Law  pro- 
ceeded on  the  assumption  that  the  intensity  of  any 
sensation  is  a  definite  quantity  made  up  of  a  certain 
number  of  units  of  intensity,  and  that  sensations  of 
different  strength  might  in  this  way  be  mathemati- 
cally compared.  This  assumption,  however,  has  been 
denied  in  toto.  A  sensation,  it  is  claimed,  is  not  made 
up  of  a  number  of  units.  Within  the  sensation  which 
an  arc-light  gives,  for  instance,  we  cannot  discern  a 
number  of  weaker  sensations,  each  like  the  light  of 
a  tallow  candle.  A  loud  sound,  as  an  experience, 
is  not  composed  of  smaller  faint  sounds ;  we  cannot 
break  it  up  into  a  weaker  sound  plus  a  certain  in- 
crement ;  it  is  an  absolutely  indivisible  and  unitary 
experience. 

This  is  certainly  a  forcible  argument,  and  yet  I  am 
not  sure  that  we  should  give  it  decisive  weight.  For 
might  we  not  similarly  point  out  the  absurdity  of  at- 
tributing spatial  quantity  to  trees,  since  a  big  tree  is 
not  a  collection  of  little  trees,  nor  can  we  break  the 
large  one  up  into  a  smaller  tree  plus  a  certain  incre- 
ment ;  the  larger  tree  is  not  a  compound,  it  is  a  single 


or  th~    ^ 


Nl^ 


Fig.  12.  —  Apparatus  for  producing  an  after-image  of  motion,  in 
direction  the  reverse  of  the  original  movement. 


Possibility  of  Mental   Measurements       49 

and  unitary  thing.  And  yet  it  is  not  the  less  a  space- 
extent.  So  that  even  if  we  admit  that  each  mental 
event  is  something  entirely  unique,  this  does  not 
preclude  its  having  some  single  aspect  —  like  that  of 
quantity  —  common  to  other  mental  events.  Any- 
thing in  the  world,  whether  it  be  a  tree  or  so  simple 
a  thing  as  a  sensation,  has  many  sides,  and  nobody 
should  pretend  that  the  quantitative  aspect  is  more 
than  a  single  one  of  these,  hidden  among  many 
others,  and  recognizable  only  by  a  subtle  process  of 
abstraction  whereby  the  numberless  differences  and 
contrasts  between  this  and  other  objects  are  for  the 
time  neglected.  One  need  not  discover  little  trees  in 
the  large  one,  nor  even  yardsticks  in  it,  in  order  to 
attribute  to  it  linear  quantity.  We  neglect  the  differ- 
ence in  wood  between  the  tree  and  the  yardstick ; 
wQ  neglect  their  difference  in  shape  and  color,  as 
well  as  the  fact  that  at  bottom  a  tree  is  not  a  com- 
pound but  is  an  organic  unit,  and  cling  to  the  sheer 
abstract  extent  which  both  objects  display.  Similarly  An  indivisi- 
the  loud  sound  undoubtedly  does  come  to  us  as  a  bieexpen- 

-'  ence  may  be 

unitary  thing  and  not  as  a  compound.  It  arouses  quantitative, 
feehngs  and  impulses  that  are  totally  different  from 
thjose  of  a  faint  sound,  so  that  as  an  experience  it 
has  a  peculiar  quality  and  flavor  which  the  other 
lacks.  And  yet  this  does  not  argue  that  the  two 
lack  the  single  common  feature  of  strength  as  a 
strictly  quantitative  matter.  Whether  it  is  possible 
to  measure  and  mathematically  express  their  relative 
strength  —  that  is  another  question,  to  be  discussed 
later.  Here  we  are  concerned  solely  with  the  high- 
handed objection  that  there  is  no  quantity  in  mental 


5©  Experimental  Psychology 

things  to  measure,  and  that  we  may  consequently  with- 
out more  ado  declare  all  attempts  to  measure  them 
futile  and  absurd.  And  so  far  as  the  present  argu- 
ment goes,  we  may  bring  in  a  verdict  of  not  proven. 
Yet  even  if  It  ought  perhaps  to  be  added,  that  this  particular 

should?  ii  question  in  regard  to  the  intensity  of  mental  processes 
all  is  not  lost.'  does  not  sccm  to  me  so  vital  for  even  our  laboratory 
measurements  (not  to  speak  of  the  large  amount  of 
work  that  does  not  pretend  to  measure  anything)  as 
many  have  supposed.  The  justification  of  the  quan- 
titative work  does  not  stand  or  fall  according  as  we 
can  allay  all  doubt  of  the  existence  of  intensive 
quantity  in  sensations.  For  even  should  we  concede 
the  whole  point,  there  still  remain  plenty  of  other 
kinds  of  quantity  (such  as  temporal,  spatial,  and 
merely  numerical  quantity)  to  give  scope  for  research 
in  measurement.  And  as  a  matter  of  fact,  the  most 
systematic  attempt  that  has  yet  been  made  to  sweep 
away  the  notion  of  intensive  quantity  from  psychol- 
ogy does  not,  in  the  end,  really  exclude  all  quantita- 
tive character  from  our  sensations,  but  simply  reduces 
intensity  to  quantity  of  another  sort,  to  differences  of 
time  and  space.  According  to  this  attempt  at  recon- 
struction, a  loud  sound  seems  to  be  more  intense  be- 
cause it  occasions  in  us  reflex  muscular  contractions 
of  longer  duration  and  of  wider  extent  than  does  a 
faint  sound.  The  involuntary  muscular  reaction  per- 
sists through  more  time  or  is  diffused  through  more 
space,  and  this  purely  temporal  or  spatial  difference 
in  the  muscular  accompaniment  somehow  casts  its 
shadow  over  the  auditory  impression  and  gives  to  it 
the  pecuUar  appearance  which  we  call  its  intensive 


Possibility  of  Mental  Measurements       51 

character.  Passing  over  the  obvious  difficulty  here 
that  our  muscular  sensations  seem  also  to  have  inten- 
sity in  addition  to  their  temporal  and  spatial  character 
(so  that  we  are  as  far  as  ever  from  ridding  ourselves 
of  intensity),  the  question  sifts  down  to  one  of  classi- 
fication, —  whether  intensity  is  a  special  and  separate 
kind  of  quantity,  or  can  be  reduced  to  one  of  the 
other  kinds ;  and  the  experimenters  can  work  as  con- 
tentedly under  one  answer  to  this  problem  as  under 
the  other.  It  really  makes  little  difference  to  them 
whether  psychic  quantities  be  thrown  into  one  group 
more  or  one  group  less.  That  there  should  be  quan- 
tity at  all  is  the  main  thing ;  not  that  there  should  be 
quantity  of  this  or  that  particular  name. 

As  to  the  existence  of  spatial  quantity  in  the  psy-  2.  Spatial 
chic  realm,  it   has  been  usual   for  psychologists  to  ^^^"^^*y  ^'^ 
make  no  claim  in  that  direction.      Physical  things,  realm, 
it  is  held,  have  shape  and  size  and  position ;  but  men- 
tal processes  not.     Our  thought  of  a  quart  is  not  a  Arguments 
larger  thought  than  that  of  a  pint.     Our  conception  '^°^^^^' 
of  the  north  pole  does  not  lie  to  the  north  of  our 
conception  of  the  south  pole.      The  idea  of  half  a 
circle  is  not  a  semicircular  idea,  etc. 

There  certainly  is  no  disputing  these  propositions. 
But  they  do  not  prove  that  space-relations  have  no 
place  in  psychology ;  they  merely  show  that  space  is 
not  a  universal  form  of  our  mental  processes.  For 
we  could  as  well  argue  that  mental  facts  have  no 
time-character,  since  our  idea  of  a  century  is  not  it- 
self a  century  long ;  or  that  color  is  a  purely  physical 
phenomenon  and  not  at  all  a  psychological  one,  since 
our  idea  of  green  is  not  a  green  idea. 


5' 


Experimental  Psychology 


A  distinction.  The  confusion  clears  up  somewhat  when  we  dis- 
tinguish between  the  object  in  mind  and  certain 
deeper  mental  processes  that  play  around  this  object. 
Now  space-character  may  justly  be  attributed  to  the 
object  we  have  in  mind,  and  yet  be  confessedly  in- 
applicable to  the  higher  mental  activity  that  stands 
above  and  around  the  mental  object  or  contents.  In 
other  words,  some  of  our  more  elaborate  processes  do 
not  have  the  same  characteristics  that  the  particular 
constituents  of  these  processes  possess.  And  conse- 
quently when  we  have  shown  the  absurdity  of  assign- 
ing spatial  quantity  in  the  one  case,  we  are  far  from 
driving  this  quantity  quite  out  of  the  psychological 
field. 

Such  an  expulsion  would  be  easier  if  there  were 
not  so  many  space-objects  that  have  their  existence 
only  in  consciousness,  so  that  their  spatial  character 
cannot  be  coolly  turned  over  to  the  physical  world. 
The  pecuhar  shapes  and  dimensions  of  many  figures 
are  sheer  figments  of  the  mind,  as  in  our  dreams  or  in 
the  normal  illusions  of  our  waking  state.  The  quan- 
titative aspect  of  these  objects  is  clearly  a  mental  af- 
fair, and  any  measurements  we  might  perform  would 
be  a  psychological  measurement,  pure  and  simple. 

lUustrations.  The  interesting  illusion  that  goes  by  the  name  of 
Zollner's  figure  might  illustrate  such  a  non-physical 
spatial  quantity.  In  this  illusion  parallel  lines  cease 
to  appear  parallel  as  soon  as  they  are  cross-hatched, 
as  in  the  accompanying  diagram  (Fig.  7).  The  ap- 
parent displacement  of  the  parallels  amounts,  in  my 
own  case,  to  an  angle  of  about  four  degrees.  So  that 
if  the  diagram  be  changed  four  degrees  in  the  opposite 


Difficulty  of 
denying 
space-attri- 
butes to  the 
mind. 


Possibility  of  Mental  Measurements        53 

direction  to  offset  the  illusory  effect  (as  in  Fig.  8), 
the  lines  appear  to  be  parallel.  The  disturbance 
caused  by  the  cross-hatching  is  a  psychological  fact, 
and  is  quantitative  and  spatial.  It  may,  in  the  end,  be 
due  to  some  purely  intensive  effect  of  the  cross-lines 
upon  the  muscles  of  the  eye,  although  probably  not ; 
but  as  we  experience  it  the  illusion  is  spatial^  and  as 


Fig.  7.  —  The  lines  AB  and  CD 
are  really  parallel. 


I,  ^ 


Fig.  8.  — The  lines  AB  and  CD  con- 
verge upward.  The  psychologi- 
cal effect  of  the  cross-hatching  is 
measured  by  the  angle  DCD', 
since  CD'  is  parallel  to  AB. 
(ZDCD'  =  4°+). 


such  we  have  to  describe  and  measure  it.  Similarly  the 
apparent  enlargement  of  the  sun  and  moon  when  near 
the  horizon  is,  in  all  probability,  a  mental  phenomenon, 
nd  is  of  course  spatial.  So  that  it  would  not  seem 
amiss  to  make  spatial  quantity  a  valid  category  in  psy- 
chology ;  but  valid  only  within  limited  regions,  as  has 
been  said,  and  not  of  universal  application.^ 


1 1  have  the  less  hesitation  in  presenting  these  conclusions  in  regard 
to  the  spatial  character  of  mental  phenomena,  as  well  as  in  regard  to 
their  intensity,  since  finding  that  my  view  is  in  essential  agreement  with 


54 


Experimental  Psychology 


3.  Tempo- 
ral quantity. 


Reasonable- 
ness of 
assuming  it. 


4.  Quantity 
of  simple 
enumeration 


It  is  less  difficult  to  convince  ourselves  that  tem- 
poral quantity  has  a  place  in  the  mental  realm.  It  is 
true  that  for  certain  ends  it  is  often  necessary  to 
regard  the  mind  sub  specie  ceterni^  and  to  neglect 
that  side  of  it  that  shows  duration  and  change.  But 
whatever  aspects  of  the  mind  there  may  be  that  are 
timeless,  they  are  certainly  not  the  ones  with  which 
empirical  psychology  has  most  to  do.  Psychology  is 
largely  concerned  with  acts  of  attention,  with  pleas- 
ure and  pain,  with  the  processes  of  perception  and 
memory ;  and  can  we  justly  maintain  that  these  in 
their  secret  essence  are  timeless .''  They  have  all 
the  characteristics  of  events  in  time;  they  come 
and  go;  some  are  brief  while  others  persist;  they 
come  together;  they  come  in  succession.  A  re- 
cent writer  has  denied  that  mental  phenomena  are 
temporal ;  but  it  is  difficult  to  see  any  better  reason 
for  this  than  there  would  be  in  the  case  of  the 
phenomena  of  physics  or  of  astronomy  or  of  history. 
Psychology  has  as  good  ground  for  assuming  the 
reality  of  time  within  its  own  field  as  have  any  of 
the  sciences. 

And  finally,  if  we  are  to  complete  our  review  of 
the  quantitative  aspects  of  the  mind,  we  shall  have  to 
include  still  another,  and  that  the  most  abstract  of 
all.  Professor  Howison  has  clearly  shown  that 
wherever  any  real  differences  exist,  there  the  funda- 
mental notion  of  quantity,  that  of  number,  finds  a 


that  of  so  able  a  writer  as  Mr.  F.  H.  Bradley.  See  his  two  articles 
in  ^m</ (N.  S.,  Vol.  IV,  1895)  entitled  respectively:  "In  what  sense 
are  Psychic  States  extended?  "  and  "  What  do  we  mean  by  the  Intensity 
of  Psychic  States?" 


Possibility  of  Mental  Measurements       55 

place.  In  this  widest  sense,  quantity  pervades  the  pervades 
mental  world  as  truly  as  it  does  the  physical.^  For  in  Jeaim^"^^^ 
neither  realm  is  there  monotonous  uniformity ;  on  the 
contrary,  there  are  distinctions  and  contrasts,  and  so 
the  basis  for  number  is  at  hand.  As  regards  numeri- 
cal quantity,  then,  we  do  not  have  to  make  the  reser- 
vations that  were  necessary  in  some  of  the  other 
cases.  There  is  no  department  of  the  mind  that  it 
does  not  penetrate.  Hegel  has  shown  that  quantity  is 
next-door  neighbor  to  quality,  and  that  as  soon  as 
anything  possesses  character  it  is  ipso  facto  entering 
the  quantitative  field.  The  great  theological  debates, 
whether  God  is  one  or  many;  the  problem  of 
Monism  and  Pluralism,  of  Unitarianism  and  the 
Trinity  —  these  are  evidence  of  the  exalted  region 
into  which  men  have  felt  that  the  notion  of  number 
goes.  Whether  there  are  real  and  abiding  distinc- 
tions within  the  very  Godhead,  has  seemed  to  many 
thinkers  a  relevant  question.  To  escape  it  we  should 
have  to  adopt  something  like  the  mystical  view  that 
spirit  lies  in  a  realm  where  none  of  our  human  predi- 
cates applies ;  that  it  is  neither  one  nor  many,  nor 
many  in  one,  but  is  ineffably  higher  than  all  such 
marks.  But  certainly  no  psychologist  can  consist- 
ently accept  this  view  as  applying  to  the  mind  as 
we  actually  know  it.  For  psychology  is  an  effort  to 
understand  the  mind,  to  map  off  and  tabulate  its 
different  appearances  and  events.  And  those  who 
carefully  examine  the  subject  believe  that  many 
differences  and  contrasts  and  variations  in  conscious- 

^  Howison,  "  Philosophy  and  Science,"  University  Chronicle^  Vol.  V, 
p.  129. 


S6 


Experimental  Psychology 


ness  are  discernible.  A  process  of  reasoning  is  one 
thing,  a  sensation  of  pain  is  another ;  each  is  one  and 
the  two  are  two.  And  in  the  flicker  experiment, 
described  in  the  preceding  chapter,  some  thirty 
mental  events  occur  in  a  second.  The  fact,  however, 
that  most  of  our  mental  phenomena  dawn  and 
change  and  almost  insensibly  fade  away  and,  at 
best,  have  but  the  vaguest  outlines  is  no  better 
ground  for  denying  them  quantity  than  for  refusing 
it  to  the  clouds  because  they  are  often  ill-defined  and 
merge  and  vanish  in  thin  air. 


But  even 

though 

psychic 

quantity 

exist,  is  it 

measurable? 

Doubt  be- 
cause of  the 
inaccuracy 
of  our  experi- 
ments. 


There  seems,  then,  an  irresistible  cumulative  evi- 
dence that  mental  phenomena  are  quantitative.  The 
remaining  and  more  practical  question  is  whether 
this  quantitative  character  is  really  measured  by  our 
laboratory  experiments. 

Perhaps  the  readiest  doubt  would  be  on  the  score 
of  accuracy.  The  illustrations  given  earlier  in  this 
chapter  indicate  the  difficulties  and  embarrassments 
under  which  psychology  labors  in  this  regard.  Our 
results  certainly  make  a  poor  showing  in  comparison 
with  the  marvellous  exactness  which  marks  the  best 
physical  measurements.  In  computing  the  amount 
of  purplish  red  cast  over  the  gray  by  contrast  with 
the  green,  —  one  of  the  examples  of  psychological 
measurement  given  some  pages  before,  —  if  we  car- 
ried out  the  measurement  in  all  its  details  we  should 
be  struck  by  the  impossibihty  of  making  any  very 
exact  determination  of  the  amount  of  red  the  green 
induced.  In  our  attempt  to  match  the  red,  we  should 
find  that,  when  once  we  had  reached  a  certain  point. 


Possibility  of  Mental  Measurements       57 

a  few  degrees  of  red  more  or  less  in  our  meas- 
uring wheel  would  not  disturb  the  match  to  any 
appreciable  extent ;  it  would  seem  satisfactory  re- 
gardless of  the  exact  amount  of  the  red  sector  dis- 
played, provided  we  kept  within  certain  limits.  In 
any  single  measurement,  therefore,  there  is  always 
the  probability  of  a  considerable  error.  And  this 
holds  true  of  all  our  other  psychological  measure- 
ments,—  in  the  examples  of  experiments  on  the  tactile 
sensibility  of  the  blind  and  in  the  chronometric  work 
which  at  first  sight  might  seem  to  an  untrained 
person  a  marvel  of  accurate  investigation.  Judged 
by  the  standards  of  astronomy  or  of  physics,  how- 
ever, such  work  is  crude  enough,  and  marks  off  the 
result  as  by  a  ploughshare  where  the  others  can  use 
a  graver's  tool. 

But  admitting  all  this,  I  feel  that  too  much  stress  Even  exact- 
can  be  laid  on  a  matter  so  important,  even,  as  that  of  "^^^  ^^"  ^® 

^  overvalued. 

accuracy  in  measurement.  Exactness  is  certainly  a 
vital  thing,  and  the  psychological  work  must  become 
vastly  more  refined.  But  accuracy  is  relative,  after 
all ;  and  what  we  call  the  exact  physical  sciences  AU  measure- 
appear  so  only  because  we  have  no  absolutely  exact 
measurements  with  which  to  compare  theirs.  Even 
in  astronomy  the  measurements  are,  strictly  speaking, 
but  rough  approximations.  Yet  the  errors  here  offer 
no  insuperable  obstacle  to  reliable  generalizations. 
Copernicus  and  Galileo  in  their  most  lasting  work 
doubtless  relied  on  observations  which  would  be 
considered  crude  if  judged  by  the  standards  of  our 
modern  observatories,  and  cruder  still  could  we  but 
look  back  upon  them  from  the  vantage  of  the  coming 


ments  are  in- 
exact. 


58 


Experimental  Psychology 


Importance 
of  knowing 
the  range 
of  error. 


Valid  infer- 
ences from 
results  that 
contain  error. 


years.  It  is,  therefore,  no  fatal  objection  to  our  psy- 
chological measurements  that  they  are  comparatively 
rough.  Moreover,  increased  success  is  constantly 
being  attained  in  excluding  various  sources  of  error 
and  in  measuring  or  estimating  the  amount  of  the 
errors  themselves.  When  once  we  know  how  large 
the  error  in  any  given  instance  is,  it  often  ceases  to 
be  a  serious  disturbance.  As  far  as  the  special  prob- 
lem in  hand  is  concerned,  we  may  proceed  as  if  the 
results  were  accurate  to  a  hair.  If  we  found,  for 
example,  that  when  the  contrast  experiment  was  tried 
in  the  presence  of  music,  one  or  two  degrees  more 
of  red  appeared  in  our  results,  we  should  hardly  be 
justified  in  concluding  that  music  tended  to  heighten 
the  effect  of  color  contrast.  One  or  two  degrees  are 
too  small  in  comparison  with  the  probable  error  of 
measurement.  But  should  our  results  regularly  run 
up  twenty  or  twenty-five  degrees  whenever  the  music 
was  heard,  we  might  justly  feel  some  premonitory 
emotions  of  discovery.  Or  to  take  a  case  actually 
tried,  we  do  find  that  when  a  sharp  line  is  drawn 
between  the  green  and  the  gray  the  results  show  such 
a  falling  off  in  the  amount  of  apparent  red  that  it  is 
impossible  to  attribute  it  to  an  error  of  observation ; 
we  are  sure  that  it  is  a  psychological  effect  produced 
in  some  way  by  the  line.  In  spite  of  the  roughness 
and  error  of  the  measurement  here,  we  may  unhesi- 
tatingly conclude  that  the  effect  of  the  green  upon 
the  gray  is  heightened  by  a  certain  lack  of  definition 
in  the  impressions  themselves.  Largely  for  this  rea- 
son, contrast  tints  in  the  landscape  are  best  seen 
through  half-closed  eyes. 


Possibility  of  Mental  Measurements       59 

This  seems  to  me  to  break  the  force  of  the  ob- 
jection based  on  the  inexactness  of  the  laboratory 
experiments.  No  measurements,  whether  they  be 
psychic  or  physical,  are  exact  beyond  a  certain  point, 
and  the  art  of  using  them  consists  largely  in  checks 
and  counter-checks,  and  in  knowing  how  far  the 
measurement  is  reliable  and  where  the  doubtful  zone 
begins.  And  all  this  is  quite  possible  in  the  case  of 
psychological  research. 

More   acute   and   more   difficult  of   answer  is  the  objection 
objection  that  the  laboratory  work,  exact  or  inexact,  *^^^^^\psy- 

J  _         •/  '  '    cnological 

does  not  measure  anything  mental  at  all ;  that  what  measure- 
is  really  measured  in  each  case  is  some  purely  physi-  J^^"j^^  ^^^ 
cal  fact  —  the  excitation  in  our  nerves  or  even  some  physical 
process  in  the  world  outside  our  bodies.     Serious  as 
this  objection  at  first  appears,  it  need  hardly,  however, 
disconcert  us. 

For,  in  the  first  place,  we  must  except  from  any  certainly 
doubt  of  this  kind  the  experiments  on  the  duration  of  ^°^to"t^^e^ 
mental  phenomena.     If  I  look  at  my  watch  and  see  measure- 
how  long  it  takes  me  to  run  through  a  chain  of  ten 
associations    starting  say  with  Transvaal,  Transvaal 
reminding  me  of  Krueger,  this  the  Kriegervereiny  the 
Franco-Prussian  War,  Paris,  the  Revolution,  Carlyle, 
the   burning  of   his   Manuscript,  John   Stuart   Mill, 
the  Logic,  —  this  process,  I  find,  takes  perhaps  ten 
seconds.     The  ten  seconds  here  are  the  duration  of 
the  mental  process,  as  nearly  as  I  can  measure  it ; 
and  not  primarily  the  time  of  some  physical  process, 
say  that  in  the  brain.     The  brain-process  correspond- 
ing to  this  train  of  ten  associations  doubtless  lasts 


ments. 


6o  Experimental  Psychology 

about  the  same  time;  but  that  is  an  inference  once 
removed ;  the  direct  observation  is  of  the  time  of  the 
ideas  and  not  of  the  operation  in  the  nerves.  The 
nervous  action  is  a  relatively  hypothetical  affair,  and 
to  time  it  I  have  to  work  back  from  my  immediate 
measurement  of  the  mental  facts.  The  measurement 
here,  then,  is  first  and  foremost  a  measurement  of 
mental  occurrences.  And  the  same  holds  true,  al- 
though perhaps  less  obviously,  of  the  delicate  time- 
measurements  in  thousandths  of  a  second,  of  which 
some  examples  were  given  earUer.  Similarly  the 
experiments  dealing  with  the  spatial  and  numerical 
character  of  our  mental  processes  are  primarily  men- 
tal measurements.  Whatever  physical  quantities  we 
get  in  this  way  are  secondary  matters,  inferred  from 
the  results  of  the  mental  observations. 
The  intensive  But  when  we  pass  to  the  experiments  on  the  inten- 
measure-  gj|.y  q£  pgyc^ic  phenomena,  there  does  seem  to  be 
suspiciously  something  strange  and  suspicious.  In  the  first  place, 
physical.  j£  ^^  ^^.^  really  making  mental  measurements,  why 
are  not  our  scale  and  our  units  of  measurement  men- 
tal in  character .?  The  standard  or  unit  in  every  case 
seems  to  be  a  purely  physical  thing.  In  experiments 
on  the  sense  of  touch  we  may  use  a  series  of  brass  or 
cork  weights,  of  grammes  or  milligrammes, — a  physi- 
cal quantity,  out  and  out,  and  not  psychical  in  the  least. 
And  in  the  case  of  color  contrast  the  units  of  inten- 
sity may  be  so  many  degrees  of  a  physical  sector  of 
red  paper  of  a  certain  texture  and  hue.  But  how  can 
a  mental  phenomenon  be  measured  by  a  physical 
scale  ?  As  far  as  the  strictly  psychological  processes 
are  concerned,  must  not  our  results  inevitably  be  as 


Possibility  of  Mental  Measurements       6i 

wide  of  the  mark  as  if  we  tried  to  express  the  effect 
of  the  Choral  Symphony  in  horse-power  or  in  foot- 
pounds ? 

A  doubt  of  this  kind  is  natural,  and  yet  it  is  largely  The  units  of 
due  to  a  misunderstanding  of  the  real  nature  of  the  JJJgnt'here 
standards  of  measurement  here.     When  we  say  that  are  reaiiy 
the  reddish  contrast  amounts,  in  one  instance,  to  20°,  p^^'^^^'^- 
and  in  another  instance  to  30°  of  red  on  our  measur- 
ing wheel,  we  certainly  do  not  mean  that  it  is  literally 
equivalent  to  a  certain  angle  of  a  red  paper  sector. 
That  would  be  absurd ;  the  contrast  effect  is  not  an 
arc  or  an  angle  at  all.     The  more  pronounced  red  in 
our  revolving  measure-disk  is,  as  we  directly  experi- 
ence it,  a  purely  intensive  effect.     For  convenience' 
sake,  we  designate  the  different  intensities   by  the 
angular  measurement  of  the  sector  which  produces 
them.      But  what  we  are  really  working  with  is  a 
scale  of  intensive  experiences.     Our  scale,  or  meas- 
ure, is  psychic,  although  we  speak  of  the  different 
points  on  the  scale  in  physical  terms. 

And  the  same  is  true  of  experiments  with  weights, 
although  not  of  all.  We  find,  for  example,  that  under 
one  very  definite  set  of  conditions  a  person  can  just 
feel  the  difference  between  a  weight  of  100  grammes 
and  one  of  1 30  grammes ;  but  if  we  slightly  alter  the 
conditions  the  same  person  can  distinguish  between  a 
weight  of  100  grammes  and  one  of  103  grammes. 
We  use  here  the  language  of  physical  weights,  but 
in  reality  we  are  dealing  with  the  sensations  which 
the  weights  produce.  We  find  that  by  regular  grada- 
tions of  pressure  upon  the  skin  we  can,  within  cer- 
tain limits,  produce  a  graduated  scale  of  sensations 


62  Experimental  Psychology 

running  from  a  barely  perceptible  touch  up  to  a 
degree  of  violence  where  touch  is  swallowed  up  in 
pain.  This  series  of  sensations  is  the  real  psycho- 
logical scale,  and  the  brass  weights  are  the  mere 
machinery  for  getting  this  before  us.  There  is  no 
ground  here  for  the  charge  that  our  standards  of 
measurement  are  physical  and  not  mental. 

But  are  these  But  as  regards  the  intensity  of  mental  phenomena 
and^invari-  ^^^  department  which,  all  along,  has  given  the  most 
able  ?  trouble),  there  is  an  additional  difficulty  which  for  the 

honor  of  the  work  one  might  feel  tempted  to  pass  by. 
There  is  certainly  something  here  that  is  quite  different 
from  our  ordinary  conception  of  measurement.  It  is 
said,  no  doubt  libellously,  that  in  the  early  Mexican 
surveys  in  California  the  measure  employed  was  a 
thong  of  rawhide  which  stretched  with  use,  and  that 
this  accounts  for  the  progressive  increase  in  the  length 
of  the  blocks,  at  Santa  Barbara,  for  instance,  as  one 
walks  back  from  the  shore.  Now  it  is  barely  possi- 
ble that  there  is  something  comparable  to  this  in  the 
psychological  measurement  of  intensity.  It  is  diffi- 
cult to  prove  that  in  these  experiments  the  unit  of 
measurement  remains  absolutely  the  same  through- 
out the  whole  stretch  to  be  measured.  For,  to  return 
to  the  illustration  of  color  contrast,  the  measurement 
was  in  terms  of  a  scale  of  color  intensities,  or  satura- 
tions, produced  by  a  regular  series  of  enlargements  of 
a  red  sector,  and  the  results  were  stated  in  degrees 
of  this  sector.  On  the  physical  scale  each  division 
of  the  arc  of  red  paper  is  exactly  like  its  fellows, 
—  the  tenth  or  the  twentieth  step  is  the  same  as  the 


Possibility  of  Mental  Measurements       6;^ 

first.  But  we  cannot  be  sure  that  this  is  the  case  in 
the  series  of  mental  intensities  produced  by  the  grad- 
ual enlargements  of  the  sector.  For  aught  we  know 
each  step  in  the  mental  scale  may  be  different  from 
its  predecessors.  All  that  can  be  confidently  said  is 
that  the  mental  series  is  composed  of  a  number  of 
small  additions,  but  we  have  no  assurance  that  every 
addition  which  we  call  by  the  same  name  is  really  of 
the  same  amount. 

In  fact,  some  have  long  felt  that  we  have  good  ex-  No  assur- 
perimental  reason  to  believe  that  any  scale  of  inten-  constaicy^^'^ 
sity  in  our  laboratories,  whether  it  be  a  series  of  reds 
such  as  has  just  been  mentioned,  or  of  pressure-sen- 
sations or  of  sound  or  temperature  or  pain,  —  that 
none  of  these  scales  is  an  ordinary  arithmetical  series 
where  each  member  is  as  good  as  its  neighbor,  but 
that  it  is  a  gradually  diminishing  series  in  which  each 
additional  step  carries  us  farther  along,  it  is  true,  but 
not  as  much  farther  as  did  the  one  before.    The  thong 
here  is  supposed  to  shrink  instead  of  stretch.     There 
are  others  who  believe,  however  (and  they  seem  to  me 
to  have  the  better  reason),  that  the  different  degrees 
or  units  of  any  given  psychological  scale  are  approxi- 
mately uniform  throughout.     But  this  is  still  debat- 
able ground,  and  the  decision  must  be  reached,  if  at 
all,  by  further  patience  and  experimental  sagacity. 
Until  a  solution  is  found  our  quantitative  results  in  re- 
gard to  intensity  must  give  forth  an  uncertain  sound. 
And  yet,  even  before  this  defect  shall  have  been  made  This  does 
good,  such  measurements  are  by  no  means  useless  or  "°*  u^v^iue- 
'  without  significance.      In  spite  of  their  uncertainty  less. 
they  may  serve  as  the  basis  for  wide  inductions.    We 


64  Experimental  Psychology- 

must  simply  avoid  the  obscure  portion  of  our  results 
and,  as  all  scientists  must  do,  base  our  inferences  only 
on  the  portions  that  are  sure.  But  it  may  not  be 
out  of  place  to  repeat  that  the  worst  difficulties  are 
confined  to  that  single  class  of  experiments  which 
would  measure  the  intensity  of  mental  occurrences, 
and  are  not  present  in  those  dealing  with  the  tem- 
poral or  spatial  or  merely  numerical  quantity  of  the 
phenomena. 

The  purpose  And  now  a  word  as  to  the  purpose  of  these  meas- 
mente^^"^^"  urements.  Suppose  that  the  measurements  are  walid, 
one  might  ask,  of  what  use  are  they  ^  It  has  been 
claimed  that  there  is  a  vast  difference  in  the  purpose 
of  mental  and  of  physical  measurements ;  that  physi- 
cal measurements  are  for  their  own  sake  —  are  an  end 
in  themselves  —  whereas  mental  measurements  are 
not.  The  truth  is,  that  no  sane  person  ever  measures 
anything,  whether  it  be  physical  or  mental,  just  for 
the  sake  of  measuring  it.  He  measures  in  order  to 
discover  the  interrelations  of  things.  If  the  men- 
suration is  not  for  some  practical  end,  Uke  that  of 
fitting  garments  or  of  navigating  the  seas,  it  is  for 
the  higher  utilities  of  intelligence  —  for  the  sake  of 
understanding  the  relationships  and  laws  in  nature. 
We  measure  mental  processes  for  a  like  purpose,  to 
discover  their  connections  and  kinships.  Psychology, 
like  all  the  sciences,  is  earnestly  concerned  with  lay- 
ing bare  the  causes  and  circumstances  of  the  vari- 
ous facts  with  which  it  deals,  and  since  mensuration 
is  of  great  assistance  in  attaining  this  result,  one  can 
well  understand  the  interest  a  psychologist  takes  in 


Possibility  of  Mental  Measurements       65 

the  general  inquiry  we  have  had  before  us  in  this 
chapter. 

It  is  because  the  question  of  mental  measurements  Conclusion, 
is  thus  an  important  one  for  the  laboratory  work  that 
so  long  a  review  has  been  made  of  the  weightier  ob- 
jections to  the  quantitative  method.  One  might  feel 
tempted  to  say  that  something  must  be  wrong  where 
so  many  objections  can  be  raised.  There  is  no  need, 
however,  of  drawing  this  conclusion.  After  all,  as 
Cattell  has  said  in  regard  to  these  difficulties,^  objec- 
tions can  be  raised  to  anything.  In  the  present  case 
the  work  is  comparatively  new,  and  seems  to  be  more 
revolutionary  than  it  really  is ;  and  withal  a  good  deal 
of  partisan  feeling  has  been  aroused  both  within  and 
without,  with  a  resultant  tendency  either  to  magnify 
or  to  belittle  the  whole  thing.  Undoubtedly  a  better 
understanding  will  come  about  in  due  season ;  and  in 
the  meantime  the  experimenters  do  not  seem  inclined 
to  wait  until  the  doubters  are  all  silenced.  The  work 
goes  merrily  on,  and  the  outlook  is  bright.  The  few 
examples  already  presented  will  perhaps  enable  one 
to  see  the  general  character  of  such  experiments  and 
the  leverage  they  offer  for  prying  into  the  recesses 
of  the  mind.  In  the  later  chapters  there  will  be  op- 
portunity to  become  further  acquainted  with  the  prac- 
tical uses  of  this  quantitative  work. 

1  Cattell, "  Presidential  Address  "  [on  the  history  and  value  of  experi- 
mental and  quantitative  work  in  Psychology],  Psychological  Review^ 
March,  1896. 


CHAPTER   IV 


THE  EVIDENCE  FOR  UNCONSCIOUS   IDEAS 


The  problem 
appeals  to 
the  emotions, 


smce  It 
touches  our 
most  varied 
interests. 


The  question  of  the  existence  of  unconscious  men- 
tal states  is  a  difficult  one  to  discuss  with  philosophic 
calm.  Cold  and  abstract  as  psychology  may  appear, 
it  has  its  own  schisms  and  heresies,  its  own  emotional 
problems,  the  answers  to  which  determine  whether 
one  shall  be  numbered  with  the  orthodox  or  with  the 
wayward. 

In  the  first  place  the  recognition  of  unconscious 
ideas  savors  strongly,  at  the  present  time,  of  psycho- 
logical ^<^^;^/<r?///5^,  —  of  thought-transference,  of  spir- 
itistic communications,  and  all  that  goes  with  the 
term  "psychical  research."  Moreover,  there  seems 
to  be  an  intimate  connection  between  the  doctrine  of 
the  unconscious  and  that  of  pessimism.  The  Oriental 
philosophies  incline  to  both.  Consciousness,  accord- 
ing to  most  eastern  thinkers,  is  the  source  of  all  evil, 
and  blessed  Nirvana  is  to  be  attained  only  by  a  return 
to  the  reality  of  life,  which  is  unconscious.  Amongst 
us  such  a  view  is  expressed  in  Wagner's  Tristan 
und  Isolde^  and  is  worked  out  in  philosophic  detail 
in  the  writings  of  Von  Hartmann.  Finally  the  doc- 
trine seems  to  strike  at  the  very  roots  of  psychology 
itself.  There  has  already  been  occasion  to  speak  of 
the  rdle  which  introspection  plays  in  the  study  of 

66 


Evidence  for  Unconscious  Ideas  67 

mind.  All  the  work  in  psychology,  whether  it  be 
physiological  or  comparative  or  experimental,  rests 
ultimately,  as  was  said,  on  the  validity  of  this  intro- 
spective method.  But  if  we  were  once  to  admit  the 
existence  of  mental  processes  which  elude  the  keenest 
self-observation,  it  would  appear  that  introspective 
evidence  were  no  longer  decisive  and  that  there  were 
room  in  psychology  for  all  manner  of  vain  guess- 
work and  imagination.  It  seems  to  unsettle  the 
foundations  of  the  faith,  and  those  who  have  at  heart 
the  interests  of  the  work  must  ward  off  the  thought 
in  very  self-defence.  The  notion  of  the  unconscious 
is  consequently  a  source  of  anxiety  to  the  conserva- 
tives, and  even  to  some  who,  like  Professor  William 
James,  have  a  radical  strain  in  them.  To  his  mind, 
this  doctrine  is  "the  sovereign  means  for  believing 
what  one  likes  in  psychology,  and  of  turning  what 
might  become  a  science  into  a  tumbling-ground  for 
whimsies."  ^ 

Because  of  these  wider  connections  of  the  ques- 
tion, it  is  well-nigh  impossible  to  keep  our  judgment 
uninfluenced  by  our  sympathies.  Our  warm  blood 
compels  us  to  have  some  preference  as  to  where  the 
truth  should  lie.  Persons  especially  interested  in  the 
"borderland"  of  mind  will,  perhaps,  find  it  difficult 
to  tolerate  a  doubt  as  to  unconscious  phenomena; 
while  those  who  have  cast  in  their  lot  with  a  critical 
psychology,  or  who  feel  that  the  philosophy  of  the 
unconscious,  with  its  accompanying  pessimism,  puts 
an  end  to  morals  and  religion,  will  be  apt  to  harden 
their  hearts  at  the  bare  mention  of  the  word. 

1  James,  The  Principles  of  Psychology ,  Vol.  I,  p.  163. 


68 


Experimental  Psychology 


Perhaps  none  of  us,  then,  may  be  unbiassed ;  and 
yet,  for  the  very  reason  that  the  question  does  lead 
out  into  the  deeper  interests  of  life,  we  cannot  afford 
to  neglect  it.  We  must  review  the  evidences,  and 
especially  the  experimental  work,  that  bears  upon  the 
case. 


The  uncon- 
scious in  psy- 
chology 
seems  to 
many  a  self- 
contradic- 
tion. 


Leibnitz  and 

the  uncon- 
scious. 


Have  we  any  reason  to  believe  that  there  are  aspects 
of  experience  of  which  we  are  not  directly  conscious  ? 
In  regard  to  the  physical  world,  it  seems  intelligible 
enough  that  there  should  be  things  that  no  one  has 
ever  seen  —  stars  too  dim  to  affect  our  sight,  bits  of 
matter  too  small  for  our  microscopes  to  reach.  But 
at  first  sight  at  least,  it  seems  impossible  that  there 
should  be  anything  analogous  to  this  in  the  mental 
world.  For  does  not  the  very  essence  of  what  is 
mental  lie  in  its  being  consciously  before  us ;  are  not 
its  esse  and  its  percipi  identical .?  Lotze  has  asked  us 
what  a  pain  would  be  which  nobody  felt;  and  the 
absurdity  which  attaches  to  such  orphaned  sensations 
would  appear  to  belong  to  any  mental  fact  which 
nobody  could  observe.  To  many  the  unconscious 
has  always  seemed  a  self-contradictory  notion,  like  a 
square  circle  or  warm  ice. 

Yet  in  spite  of  the  difficulties  that  beset  such  a 
conception,  and  of  its  mystic  air,  especially  at  the 
present  day,  it  has  had  its  sponsors  among  the  most 
penetrating  thinkers.  It  was  originated,  in  fact,  by 
Leibnitz,  who  certainly  gives  an  impression  of  intel- 
lectual health  and  balance.  The  reader  will  recall 
in  Carlyle's  "  Frederick  "  the  remark  of  Queen  Sophie 
Charlotte :  "  Leibnitz  talked  to  me  of  the  infinitely 


Evidence  for  Unconscious  Ideas  6g 

little;  mon  Dieu,  as  if  I  did  not  know  enough  of 
that."  This  thought  of  the  infinitely  little,  which  is 
the  kernel  of  his  mathematical  discovery  of  the  in- 
finitesimal calculus,  was  also  given  by  him  a  psycho- 
logical application.  According  to  his  view,  there  are 
infinite  degrees  of  mental  life,  from  clear  and  perfect 
intellect,  through  consciousness  that  is  like  a  dream, 
down  to  that  of  creatures  existing  as  in  a  swoon  or 
dreamless  sleep.  And  since  each  creature  is  the 
world  in  miniature,  —  a  mirror  of  the  universe, — 
and  since  each  recapitulates  the  whole  series  of  crea- 
tures below  it,  we  find  in  each  human  mind  a  scale 
of  mental  gradations  corresponding  to  the  scale  of 
creatures :  clear  thoughts,  obscure  and  dreamy  im- 
pressions, and  finally  those  that  he  below  the  level  of 
consciousness,  too  faint  and  confused  to  be  perceived. 
These  last  he  calls  "  minute  perceptions  "  —  what  we 
should  perhaps  designate  as  subconscious  or  sublimi- 
nal ideas.  To  use  his  illustration,  we  hear  in  the 
distance  the  roar  of  the  sea,  produced  by  the  sound 
of  the  separate  waves.  Each  individual  wave  must 
produce  in  us  some  subconscious  effect;  for  if  the 
effect  of  each  wave  were  zero,  we  could  never  ac- 
count for  the  actual  roar  we  hear.  It  cannot  of 
course  be  made  up  of  a  number  of  zero  quantities; 
it  consequently  must  consist  of  a  host  of  impressions 
exceedingly  minute.^ 

I    shall   not   attempt  to   trace   the  history  of  this  Present-day 
thought  since  Leibnitz's  day.     It  was  caught  up  and  l^^'^^^^^^ '" 
passed  along  to  our  modern  psychology,  where  it  has 
found  lodgement  even  amongst  many  who  give  little 

1  Leibnitz,  O^era  Philosophical  ed.  Erdmann,  p.  197. 


70 


Experimental  Psychology 


"  Alterations 
of  personal- 
ity." 


Evidence 

from 

memory. 


recognition  to  any  save  our  sober,  common  mental 
phenomena.  Nor  can  we  well  consider  more  than  a 
few  of  the  varied  arguments  by  which  this  view  is 
supported  in  our  time.  Those  who  ardently  believe 
in  unconscious  mental  operations  find  evidence  for 
them  in  almost  every  act  that  we  perform  :  in  our 
instincts,  in  our  habits,  in  the  short-circuiting  which 
takes  place  at  times  in  association,  as  well  as  in  the 
common  operations  of  sense.  But  the  main  em- 
phasis is  laid  on  certain  derangements  of  mind,  par- 
ticularly on  those  strange  lapses  of  memory  by  which 
whole  regions  of  a  man's  experience  pass  from  view, 
accompanied  as  this  often  is  by  an  equally  strange 
return  of  long-forgotten  portions  of  the  past.  In 
extreme  cases  this  leads  to  the  so-called  mutations  of 
personality,  somewhat  ^  as  Stevenson  has  portrayed 
them  in  his  "Dr.  Jekyll  and  Mr.  Hyde."  Such 
phenomena,  in  connection  with  similar  facts  that 
develop  in  the  hypnotic  state,  are  now  made  much 
of  as  testimony  for  a  subconscious  life.  Cataclysms 
of  this  kind,  it  must  be  confessed,  put  psychology  to 
the  test ;  its  present  system  seems  hardly  able  to  sup- 
port such  strange  occurrences. 

And  yet,  if  we  could  but  rid  ourselves  of  the 
blinding  effect  of  custom,  the  commonest  act  of  for- 
getting or  of  recollection  would  not  seem  one  whit 
less  mysterious  than  these  other  more  striking  phe- 
nomena. To  say  that  the  facts  of  double  or  of  multi- 
personality  are  but  morbid  exaggerations  of  processes 
we  perform  every  day,  of  course  does  not  explain  them, 
but  it  at  least  puts  us  in  a  position  to  see  that,  as  far 
as  the  reality  of  an  unconscious  stratum  of  experience 


OF  THE  ^ 

I/NIVERSITV  > 
Evidence  for  \Incpnscious  Ideas  71 

is  concerned,  we  can  as  well  infer  it  from  the  one  case 
as  from  the  other.  The  fact  that  to-day  I  can  recall 
experiences  which  had  faded  away  during  the  night, 
and  that  in  the  dream  state  the  mind  of  the  most  staid 
of  us  may  drop  its  usual  contents  and  live  for  hours 
in  a  mental  whirl  of  dime-novel  adventure,  is  just 
as  good  or  bad  evidence  for  unconscious  ideas  as  the 
fact  that  Krafft-Ebing's  poor  patient  lima  S.  could 
sing  Magyar  songs  and  secrete  articles  while  in  an 
abnormal  state  of  mind,  and  know  nothing  of  these 
acts  until  the  same  state  was  reinduced.^ 

Where  were  the  experiences  that  they  could  com-  what 
pletely  disappear  and  yet  be  recalled  when  the  hyp-  ^^g^oTten^^ 
notic  condition  was  resumed  ?     Likewise  we  may  ask,  ideas  ? 
Where   are   our   waking   thoughts,   our   scruples   of 
conscience,  our  pride  and  prejudice,  that  we  can  dis- 
miss them  in  our  dreams  and  yet  find  them  awaiting 
us  when  we  drop  our  play  character  and  return  to  the 
serious  concerns  of  life  ?     In  all  these  cases  there  is 
a  lapse  of  ideas  from  consciousness,   and   yet,  evi- 
dently, some  kind  of  persistence  of  them  since  we 
again  meet  them  at  a  later  date.     The  readily  sug- 
gested explanation  is  that  in  the  interim  these  ideas, 
as   ideas,  continue  their  existence  in  some  subcon-  , 
scious  limbo  where  they  await  their  recall. 

Such  a  doctrine,  however,  appeals  more  strongly  ideas  are 
to  the  imagination  than  to  the  intellect.     Ideas  and  ^of  substan- 
experiences  are  not  stable  objects  that  can   be  laid  tiai  things, 
away  on  our  psychological  shelf.     They  are  processes, 
or  acts,  of  the  mind,  and  are  as  perishable  as  the  acts 

1  Krafft-Ebing,  An  Experimental  Study  in  the  Domain  of  Hypno- 
tism, tr.  by  Chaddock,  New  York,  1896,  p.  59. 


72  Experimental  Psychology 

They  may  be  of  the  body.     We  Can  in  either  case  perform  the  act 
buTare^^'       again  and  again,  and  can  add  to  it  the  further  act  of 
never  lit-        rccognizing  that  it  is  something  that  we  have  done 
servJd!'^^'      before.      But   it  is  as   difficult  to  beHeve   that  the 
mental  process,  as  mental  process,  can  be  stored  up, 
as  it  would  be  to  believe  that  the  present  movement 
of   my  arm  is  a  reincarnation  of   the  identical  arm 
movement  I  performed  an  hour  ago,  which   in   the 
meantime  had  continued  its  existence  in  some  inter- 
mediate state. 
But  may  not        But  this  might  be  said  to  beg  the  whole  question. 
contrnue  sub-  Granting  that  our  ideas  are  not  solid  bodies  that  can 
consciously?   be  kept  in  storage,  but  are  mental  acts  which  exist 
only  while  they  are  being  performed,  may  not  the 
continued  existence  of  a  forgotten  idea  be  conceived 
as  an  endurance,  in  some  way,  of  the  mental  activity 
of  which  the  idea  consists  ?    The  survival  of  an  idea 
in  the  subconscious  state  would  thus  be  intelligible ; 
it  would  be  but  the  continuation,  in  a  low  degree,  of 
the  activity  which  in  consciousness  is  clear  and  above 
board.     The  recollection  of  experiences  would  then 
be  like  the  sudden  brightening  of  a  fire  that  had  all 
the  while  been  slumbering  but  not  extinguished. 

As  a  mere  matter  of  conceivability  perhaps  no  fatal 
objection  could  be  raised  to  such  a  view.  Buried  in  our 
experience  there  may  be  such  smouldering  coals.  But 
what  evidence  have  we  that  such  is  actually  the  fact } 
The  lack  of  It  is  Sometimes  assumed  that  the  recurrence  of  an 
this'^^"^^  ^^"^  idea  is  of  itself  sufficient  evidence  of  this  low  per- 
sistent activity  during  f orgetf  ulness  ;  ^  that  there  must 

^Cf.,  e^.,  Plainer,  Philosophische  Aphorismen,  ed.    1784,  Vol.  I, 
p.  103. 


Evidence  for  Unconscious  Ideas  73 

of  necessity  be  this  uninterrupted  life  of  the  idea  to 
serve  as  a  kind  of  bud  out  of  which  the  full-blown 
idea  may  again  develop  in  consciousness.  But  if  we 
cling  resolutely  to  the  notion  that  ideas  and  memories 
are  not  things  or  organisms,  then  it  is  clear  that  the 
revival  of  a  mental  image  no  more  presupposes  the 
continuance  of  the  selfsame  idea  in  low  intensity 
than  the  recurrence  of  the  movement  of  my  hand 
requires  that  during  the  time  when  the  hand  seems 
to  be  at  rest  it  shall  all  the  while  be  rehearsing  in  low 
degree  the  motion  which  is  later  to  be  performed  in 
full.  If  a  physical  movement  can  recur  after  an 
absolute  interruption,  why  may  not  a  mental  process  ? 

At  first  there  may  seem  to  be  an  unanswerable  Thepersist- 
objection  to  this  view.  If  each  of  our  thoughts,  no  ^f  the^p^as"""^ 
matter  how  often  recurring,  is  an  absolutely  new 
creation,  and  our  former  experiences  do  not  really 
endure,  how  is  it  that  these  former  experiences  exert 
such  a  vital  influence  upon  our  present  thoughts  ? 
As  an  actual  fact,  we  find  that  the  judgment  we  now 
make,  the  things  that  we  desire,  the  scenes  that  we 
can  imagine  or  recall,  are  moulded  by  the  experiences 
of  former  days.  Our  whole  outlook  is  colored  by 
these  past  impressions  and  ideas.  Does  not  this  show 
that,  whether  we  recall  the  past  or  not,  we  cannot 
sever  ourselves  from  it,  and  that  somewhere  beyond 
the  horizon  of  consciousness  these  thoughts  and 
images  must  still  exist  and  exert  their  influence  even 
within  the  circle  of  our  present  ideas } 

But  such  a  theory  does  not  in  the  least  help  us  to 
understand  the  facts,  but  is  rather  a  hindrance.  In 
the  case  of  the  body  there  is  a  similar  state  of  things 


74  Experimental  Psychology 

to  be  explained,  and   any  argument   like  this   one 

which  is  so  alluring  in  the  mental  realm  would  seem 

sheer  nonsense  or  mythology.     For  in  our  physical 

does  not        conduct  we  notice  that  our  acts  of  yesterday  influ- 

impiythe  movcmcnts  of  to-day.     In  trying  to  swim, 

continuance  •'  jo  » 

of  ideas.  you  find  that  it  makes  a  difference  whether  you  begin 
as  a  novice  or  have  grown  accustomed  to  the  stroke. 
So  the  tricks  of  voice  or  of  gait  that  we  uncon- 
sciously imitated  years  ago,  show  unmistakably  in 
our  present  physical  behavior.  But  we  should  never 
think  of  ascribing  this  behavior  to  the  literal  pres- 
ence of  those  older  acts,  forming  some  kind  of  unseen 
aura  around  us  and  exerting  a  living  influence  upon 
Whatpersists  our  present  functions.  We  should  say,  rather,  that 
isthedisposi-  ^^    former  acts  themselves  are  dead  and  gone,  and 

tion  to  cer-  °         ' 

tain  acts.  what  remains  is  not  even  a  pale  image  or  copy  of 
them,  but  that  the  person  in  enacting  them  formed  a 
habit  or  disposition^  by  which  such  acts  could  as 
often  as  he  pleased  be  reenacted,  but  never  Hterally 
preserved. 

Something  like  this  is  certainly  the  simpler  and 
more  reasonable  way  to  explain  the  apparent  per- 
sistence of  our  ideas.  Just  how  the  "  disposition  "  is 
to  be  understood  would  be  a  nice  point  to  determine, 
and  would  take  one  far  into  the  problem  of  the  inter- 
connection of  brain  and  mind,  and  into  that,  also,  of 
Ways  of  con-  psychic  and  physical  causation.  It  is  possible  that 
ceivingsuch    ^j^^   disposition    might   be   conceived    as   something 

dispositions.  r  o  o 

purely  physical,  as  a  persistent  neural  arrangement. 
This,  however,  is  not  the  only  way  to  conceive  of 
habit  in  a  psychological  sense.     We  might  believe 
1  Cf.  Stout,  Analytical  Psychology,  1896,  Vol.  I,  p.  21.     • 


Evidence  for  Unconscious  Ideas  75 

that  the  mind  of  itself  is  capable  of  regular  behavior, 
and  that  it  does  not  owe  this  solely  to  the  brain. 
Each  mental  act  that  we  perform  may  well  start  or 
strengthen  a  purely  mental  disposition  or  trick  of 
behavior,  or  bring  about  a  combination  of  simpler 
mental  habits  already  formed.  The  disposition  would 
then  be  of  the  nature  of  a  very  specialized  mode 
of  activity;  it  would  mean  that,  given  the  suitable 
conditions,  such  and  such  special  processes  would 
follow.  This  mode  itself,  of  course,  would  not  be  an 
unconscious  idea  or  an  imperceptible  mental  phenom- 
enon in  the  sense  we  are  now  considering.  These 
mental  habits  could  persist  through  comparatively 
long  periods  of  disuse.  Or,  on  the  other  hand,  the 
occasions  which  call  any  special  tendency  into  opera- 
tion might  arise  so  rarely  that  the  disposition  itself 
would  finally  become  obhterated.  The  conditions  of 
memory  and  oblivion  may  thus  be  described  in  terms 
of  mental  tendency  or  mental  habit  running  parallel 
to  the  neural  tendency  or  neural  habit  by  which  we 
describe  the  brain  side  of  the  operation.  And  there 
are  other  forms  of  explanation  should  we  wish  to 
avoid  even  a  tentative  adherence  to  the  doctrine  that 
mind  and  body  run  parallel  without  any  interaction 
whatever. 

We  may  safely  conclude,  therefore,  that  neither  the  The  argu- 
phenomenon  of  memory  nor  any  other  recurrence  of  ^^^^  ^[.°"^ 

^  J  -^  hypnotism 

ideas  gives  decisive  evidence  that  there  are  acts  of  fails  with 
our  own  minds  that  we  are  unable  to  observe.     And  *^*  ^"^^"^ 

memory. 

the  argument  from  memory  is  really  the  kernel  of 
the  various  arguments  from  hypnotism,  alterations 
of  personality,  and  the  Hke.     The  only  evidence  for 


76  Experimental  Psychology- 

unconscious  ideas  in  any  of  these  cases  is  that  masses 
of  ideas  disappear  and  reappear,  and  as  far  as  the 
logic  of  the  case  is  concerned,  it  of  course  makes  no 
difference  whether  the  mass  be  great  or  small,  impor- 
tant or  unimportant.  The  alteration  of  large  aggre- 
gations of  ideas,  such  as  occurs  in  serious  disturb- 
ances of  the  mind,  is  therefore  no  more  conclusive 
for  subconscious  mental  events  than  are  the  facts  of 
ordinary  recall. 

The  evidence       The  phenomena  of  automatic  communication,  how- 
fromauto-  misfht  sccm  to  put  the  matter  in   a   different 

matic  writing  '         0  ^ 

and  speech,  light.  The  f  acts  here  are  akin  to  those  of  alternate 
personality  already  referred  to,  with  the  difference 
that  the  contrasting  personalities  are  now  present 
simultaneously  and  can  express  themselves  through 
different  channels  at  the  same  time.  An  acquaint- 
ance of  mine  (a  highly  inteUigent,  although  some- 
what neurasthenic,  woman)  could,  while  perfectly 
conscious,  write  automatically  a  fluent  discourse  that 
was  often  a  surprise  to  her,  in  its  contents,  and  even 
a  shock  to  her  sensibilities.  Her  hand  seemed  con- 
trolled by  some  independent  mind.  And  Dr.  Hodg- 
son, reporting  experiments  on  the  ever-interesting 
Mrs.  Piper,  says  that  when  "Phinuit"  is  using  un- 
interruptedly the  medium's  voice,  her  hand  may  all 
the  while  be  carrying  on  some  active  communication 
as  from  another  personality,^  reminding  one  of  the 
story  of  Caesar  and  his  amanuenses.  Flournoy's 
recently  reported  case  of  H^l^ne  "  Smith  "  exemplifies 

1  See  the  Proceedings  of  the  Society  for  Psychical  Research^  Vol.  XIII, 
pp.  293  et  seq. 


tation. 


Evidence  for  Unconscious  Ideas  77 

the  same  thing. ^  While  oral  communications  were 
being  given,  ostensibly  from  Mars,  Flournoy  was 
often  able  to  obtain  from  the  medium's  left  index 
finger  comments  and  suggestions  claiming  to  be  from 
a  mundane  person  named  Leopold,  alias  Cagliostro. 
Such  cases  as  these  are  different  from  the  ordinary 
phenomena  of  forgetfulness.  Different  personalities, 
each  with  characteristic  tricks  of  thought,  are  present 
at  the  same  time.  The  consciousness  itself  seems 
cleft,  and  the  one  side  appears  to  be  ignorant  of  the 
occurrences  in  the  other. 

The  spiritistic  interpretation  of  these  things  would  The  spirit- 
at  once,  of  course,  destroy  their  value  as  evidence  for  pg^choioef- 
unconscious  mental  action.  If  "Leopold"  be  regarded  cai  interpre- 
as  a  distinct  mind  using  Hel^ne's  finger  as  a  means 
of  communication,  Helene's  ignorance  of  his  mental 
operations  would  not  indicate  that  these  processes 
were  unconscious  for  him.  It  would  simply  be  like 
our  own  ignorance  of  the  present  thoughts  of  the 
Emperor  of  Germany.  But  if  we  adopt  the  psycho- 
logical point  of  view,  and  regard  the  various  **  per- 
sonalities" in  a  case  like  Helene's  as  but  different 
forms  of  the  activity  of  the  one  person,  then  we  must 
acknowledge  that  in  the  end  they  may  favor  the 
doctrine  of  the  unconscious ;  but  since  we  are  as  yet 
ignorant  of  so  many  essential  features  in  these  abnor- 
mal phenomena,  one  may  well  hesitate  to  decide  just 
what  they  do  mean.  We  must  wait  for  more  light 
on  the  question  whether  the  secondary  personality's 
thoughts  (if  thoughts  they  be,  and  not  some  amazing 

1  From  India  to  the  Planet  Mars  (transl.),  New  York,  1900;  cf. 
especially  p.  120. 


78  Experimental  Psychology 

trick  of  the  nervous  system)  are  indeed  unknown  to 
the  primary  personality  at  the  time  when  the  expres- 
sive movements  are  taking  place.  For  the  most  part 
we  have  to  depend  on  the  subsequent  recollection  of 
the  person,  and  a  negative  result  here  is  quite  com- 
patible with  a  dim  consciousness  of  the  other  person- 
ality's thoughts  during  their  actual  occurrence.  It 
Parallels  from  may  be  as  in  our  dreams,  where  a  number  of  different 
sonaiities!"'^'  Personalities  occupy  the  stage  at  the  same  time, 
each  representing  a  different  point  of  view,  each 
ignorant  of  the  next  move  of  his  fellows,  and  yet 
there  is  nothing  strictly  unconscious  nor  any  absolute 
cleft  in  consciousness,  for  all  the  dramatis  personce 
are  included  in  the  larger  single  mind  which  is  their 
theatre.^  In  Flournoy's  report,  it  is  extremely  sug- 
gestive that  when  "  Leopold  "  was  presumably  in  ex- 
clusive possession  of  Hel^ne's  senses  and  reactions, 
and  remarks  were  dropped  by  persons  in  the  circle 
that  would  have  offended  the  medium,  she  apparently 
did  not  hear  them,  but,  after  the  trance,  she  showed 
by  her  conduct  for  weeks  that  the  slighting  words 
had  not  been  lost  upon  her. 

The  more  cautious  position,  then,  would  be  to  re- 
gard these  cases  as  due  to  parallel  and  relatively  dis- 
connected streams  of  activity  in  the  one  mind.  In 
all  probability  they  are  not  beyond  the  range  of  self- 

1 A  striking  instance  of  this  character  occurred  recently  to  a  friend 
of  mine.  In  a  dream  he  was  cross-examined  as  a  witness  in  court. 
The  counsel  for  the  opposing  side  (by  a  series  of  questions  narrated  to 
me)  gradually  enticed  him  into  a  situation  which  ended  in  the  wit- 
ness's immense  surprise  and  confusion.  There  was  here  no  mere  recol- 
lection of  a  past  occurrence,  but  rather  a  creation  of  a  relatively 
independent  personality. 


Evidence  for  Unconscious  Ideas  79 

observation  were  the  person  in  a  condition  favorable 
to  introspection,  or  had  he  the  training  and  interest 
needed  for  detecting  the  most  obscure  activities  of 
his  own  mind. 

But  passing  from  these  abnormal  phenomena,  an  Evidence 
entirely  different  line  of  evidence  is  suggested  by  [h°^hokiof 
what  is  known  in  modern  psychology  as  the  "  thresh-  sensation, 
old."  An  illustration  will  make  clear  the  meaning 
of  the  term  in  this  connection.  If  an  ordinary  tele- 
phone receiver  and  an  electrically  operated  tuning- 
fork  be  suitably  connected  with  a  Du  Bois-Reymond 
induction  apparatus  (Fig.  9),  the  telephone  will  re- 
peat the  low  drone  of  the  fork  with  varying  degrees 
of  loudness  according  to  the  distance  between  the 
two  coils  of  the  induction  instrument.  Beginning 
with  a  loud  note,  we  can  gradually  diminish  the  in- 
tensity until  we  reach  a  point  where  the  sound  is  just 
heard,  and  then,  as  we  pass  this  point,  the  note  is  lost. 
The  limit  between  our  consciousness  of  the  impression 
and  its  absolute  imperceptibility  is  what  is  called  the 
threshold,  —  a  warm  domestic  word,  for  which  some 
have  proposed  to  substitute  the  cheerless  term  "limen." 
The  threshold,  then,  is  the  border  of  consciousness 
in  general,  beyond  which  is  outer  darkness ;  and  the 
illustration  from  the  realm  of  sound  is  but  a  single 
case.  Similar  illustrations  might  be  drawn  from  any 
of  the  senses,  or  even  from  our  inner  life  of  memory 
or  imagination  or  feeling. 

In  the  particular  example  just  used,  when  the  sound 
crosses  the  threshold  it  apparently  ceases  to  exist 
psychologically.     But  however  that  may  be,  we  know 


8o 


Experimental  Psychology 


The  thresh- 
old seems 
to  indicate 
impercep- 
tible sensa- 
tions. 


The  analogy 
between 
brain  and 
mind  is  here 
misapplied. 


that  the  physical  stimulation  —  the  vibration  in  the 
telephone  —  continues  far  below  this  point.  Now 
many  have  thought  that  as  the  physical  stimulation 
runs  down  a  long  scale  of  intensities  below  the  point 
where  the  sound  seems  to  die  away,  so,  too,  the 
psychic  effect  must  Hkewise  have  a  gamut  of  inten- 
sities below  the  threshold.  In  other  words,  the  thresh- 
old here  would  be  the  point,  not  where  the  sound  as 
a  psychic  phenomenon  ceases  to  exist,  but  where  it 
reaches  an  intensity  too  low  for  us  to  perceive  it. 
Anywhere  between  the  intensity  of  stimulation  which 
we  consciously  perceive  and  an  absolute  zero  of  inten- 
sity there  would  be  actual  psychic  effects  of  a  sub- 
liminal or  subconscious  sort.  This  is  practically 
Leibnitz's  old  argument  from  the  roar  of  the  sea  re- 
appearing in  modern  laboratory  guise. 

The  argument,  however,  is  clearly  defective.  When 
more  closely  examined  the  reasoning  is  found  to  be 
this :  since  mind  and  brain  show  so  many  analogies 
in  their  behavior,  we  may  assume  that  the  analogy 
continues  throughout.  Why  may  we  not  reasonably 
infer,  then,  that  a  nervous  excitation  which  is  too  weak 
to  be  noticed  is  still  accompanied  by  a  dim  psychic 
process  —  by  an  unconscious  sensation  }  This  would 
seem  to  be  but  a  consistent  development  of  the  prev- 
alent doctrine  of  a  parallel  between  mental  and  ner- 
vous states.  The  difficulty,  however,  is  that  even  if 
there  should  exist  the  closest  analogy  between  the 
action  of  brain  and  mind,  the  fact  of  a  subliminal 
stimulation  would  not  in  the  least  imply  the  exist- 
ence of  a  subconscious  experience.  For  we  must 
remember  that  by  the  stimulus  we  mean  the  outer 


Evidence  for  Unconscious  Ideas  8i 

physical  irritant  which  plays  upon  the  delicate  organ 
of  sense.  The  excitation,  if  it  is  to  produce  any  psy- 
chic effect,  must  be  strong  enough  to  urge  its  way 
onward  to  the  gray  surface  of  the  brain.  If  we  knew 
that  the  subliminal  vibrations  of  the  tuning-fork  really 
excited  this  particular  region  of  the  nervous  system, 
then  our  parallelistic  assumption  would  force  us  to 
admit  that  there  must  be  some  subliminal  experience 
corresponding  to  this  low  degree  of  nervous  action. 
But  we  do  not  know  that  the  subliminal  sound  stimu- 
lates the  brain  at  all.  On  the  contrary,  the  tone  may 
be  imperceptible  just  because  it  is  too  weak  to  call 
forth  a  cerebral  response.  It  cannot  overcome  the 
resistance  along  the  way,  and  so  its  weak  energy  is 
dissipated.  According  to  this  view,  the  threshold  of 
consciousness  corresponds  to  the  point  where  the 
brain  itself  ceases  to  act.  There  would  thus  be  no 
subliminal  brain-processes  in  this  case  at  all,  and 
consequently  no  ground  for  arguing  the  existence  of 
subconscious  sensations  to  correspond  to  them.  For 
this  reason  the  argument  from  the  threshold  and  from 
the  existence  of  subliminal  stimuli,  on  which  many 
persons  from  Leibnitz  to  H  off  ding  have  placed  re- 
liance, is  after  all  unconvincing.^ 

1  Cf.  Hoffding,  Outlines  of  Psychology,  tr,  by  Lowndes,  pp.  71  ei  seq. 


CHAPTER  V 

FURTHER  CONSIDERATIONS  AS  TO   THE  UNCON- 
SCIOUS 

Further  evi-  It  is  an  axiom  of-  logic  that  the  collapse  of  any 
dis"  o^s^d  of^*  i^u^b^r  of  arguments  decides  nothing  as  to  the  truth 
or  falsity  of  the  view  they  were  intended  to  support. 
So  that  we  may  still  ask  whether  Leibnitz's  doctrine  is 
correct,  even  though  the  evidence  he  offers  be  not 
decisive.  When  we  carefully  distinguish  between 
Leibnitz's  notion  and  the  popular  view  of  unconscious 
ideas,  the  essential  features  of  his  conception  seem 
to  me  to  have  solid  support  in  the  facts.  Even  after 
rejecting  the  greater  mass  of  the  evidence,  as  we 
have  done,  there  is  a  remnant  that  cannot  be  dis- 
posed of  in  this  way. 
Ideas  are  But  this  evidence  by  no  means  indicates  the  exist- 

probabiy        eucc  of   uncouscious  idcas  as  currently  understood. 

never  uncon-  ■' 

scious.  Nor  does  it  seem  probable  that  Leibnitz  intended 

anything  of  the  kind.  When  he  argues  that,  because 
the  distant  surf  is  heard,  each  wave  must  to  some  ex- 
tent affect  us  mentally,  this  need  not  mean  that  a  sin- 
gle wave  would  arouse  in  us  a  subconscious  idea  of  a 
wavCy  —  a  picture  of  undulation  and  blowing  spray, 
such  as  is  called  up  when  we  hear  the  sound  near  by. 
Psychologically  speaking,  there  is  a  vast  difference 
between  hearing  the  low  sound  produced  by  a  distant 
breaker,  and  hearing  it  as  a  breaker.     In  the  latter 

83 


Further  Considerations  83 

case  we  not  only  catch  the  faint  sound,  but  its  full 

meaning.     It  means  to  us  sea  and  sand  and  salt  air, 

a  particular  curve  and  play  of  color  —  all  of  which 

is  not  auditory  at  all,  but  is  merely  suggested  by 

the  auditory  impression.      The  idea  of  the  wave  is 

thus  a  highly   organized  affair,  and   there   is   Httle 

reason  to  believe  that  any  such  complicated  mental 

process  takes  place  beyond  our  immediate  observation. 

But  that  there  are  relatively  bare  auditory  impres-y  But  relatively 

sions,  stripped  of  all  those  associations  which  raise  ^aresensa- 

^  ^  tions  perhaps 

them  to  the  dignity  of  an  idea,  —  too  faint  perhaps  exist  imper- 
to  arouse  their  usual  associates,  certainly  too  faint  to  ^^P^^^^* 
be  distinguished  against  the  vague  background  of 
other  sensations,  —  that  there  are  imperceptible 
occurrences  Hke  these,  in  the  psychic  realm,  there 
seems  to  be  good  reason  to  believe.  To  call  them 
unconscious  ideas  prejudices  the  case;  they  had  bet- 
ter be  termed  imperceptible  events  or  imperceptible 
phenomena. 

What  seems  to  me  satisfactory  evidence  of  their  Evidence 
existence  comes  from  a  lare:e  body  of   experiments  from^^P^"- 

^  J  r  ments  in  dis- 

which  measure  our  accuracy  of  distinguishing  im-  crimination, 
pressions.  In  every  kind  of  experience  we  find  that 
there  is  a  Hmit  to  our  power  of  discerning  differences. 
Two  lights  may  be  of  different  brilliancy,  but  if  one 
of  them  be  not  at  least  -^  brighter  than  the  other, 
they  seem  to  be  the  same.  Two  musical  notes  whose 
wave-rates  do  not  differ  at  least  a  fifth  of  a  vibra- 
tion a  second,  seem  to  the  most  deHcate  ear  to  be  of 
identical  pitch.  Similarly,  odors  or  tastes  or  touch 
sensations,  or  any  occurrences  whatever,  can  be  dis- 


84  Experimental  Psychology 

tinguished  only  so  long  as  the  difference  between  the 
impressions  is  of  a  certain  amount.  There  is  a  thresh- 
old here  not  unlike  the  one  already  considered,  except 
that  it  marks  the  point,  not  where  sensations  disappear, 
but  where  a  difference  between  them  disappears,  the 
sensations  themselves  remaining  clear  and  prominent. 
We  found  that  the  existence  of  a  subhminal  stimula- 
tion was  no  evidence  that  there  are  subliminal  sensa- 
tions ;  what  must  we  now  say  in  regard  to  a  difference 
which  cannot  be  felt  ?  Shall  we  say  that  an  imper- 
ceptible difference  in  the  mental  field  is  not  a  differ- 
ence at  all ;  that  the  very  backbone  of  a  mental  fact 
is  the  way  it  feels — its  esse  is  its  sentiri ;  and  that 
there  is  no  real  difference  between  psychic  phenom- 
ena until  the  difference  itself  is  felt?  No  answer 
can  be  given  offhand.  It  is  quite  conceivable  that 
two  different  facts  in  the  outer  world  —  two  weights, 
for  instance,  one  of  100  grammes  and  another  of 
102  grammes  —  would  produce  in  us  identical  expe- 
riences, identical  feelings  of  touch.  The  difference 
might  be  lost  somewhere  in  transit  between  hand 
and  brain,  or  if  it  actually  reached  the  brain,  there 
might  be  no  corresponding  difference  over  on  the 
mental  side. 

There  is  good  evidence,  however,  that  although  we 
cannot  perceive  a  distinction  here,  a  mental  difference 
really  exists.  If  we  compare  100  with  102  grammes, 
we  find  that  they  give  absolutely  indistinguishable 
intensities  of  pressure;  so,  too,  if  we  compare  102 
grammes  with  104.  If  impressions  that  feel  alike 
really  are  ahke,  then  the  first  is  identical  with  the 
second,  and  the  second  is  identical  with  the  third; 


Further  Considerations  85 

consequently,  the  first  must  be  identical  with  the 
third.  As  a  matter  of  fact,  however,  the  first  and 
third  weights  are  under  suitable  conditions  clearly- 
distinguishable.^  And  from  this  we  may  assure  our- 
selves that  the  sensations  arising  from  100  and  102 
grammes  are  really  different,  although  the  difference 
is  imperceptible.  For  if  they  were  identical,  they 
would  behave  alike ;  they  would  be  either  equally 
distinguishable  or  equally  indistinguishable  from  104, 
whereas  they  are  not ;  we  find  that  one  can  be  dis- 
tinguished from  the  pressure  of  104  grammes,  while 
the  other  cannot.  The  addition  of  2  grammes  to  100 
is  imperceptible,  but  it  produces  nevertheless  a  real 
alteration  of  the  mental  state.  But  of  course  such 
imperceptible  gradations  in  experience  are  not  con- 
fined to  this  single  realm  of  touch.  The  same  evi- 
dences and  the  same  argument  could  be  repeated  in 
regard  to  a  wide  variety  of  experiences,  —  in  regard 


1  Such  small  differences  are  clearly  perceived  when  an  immediate 
and  instantaneous  change  is  made  from  the  lower  to  the  higher  weight 
(though  not  when  passing  in  the  reverse  direction),  after  the  manner 
described  in  my  "  Ueber  die  Wahrnehmung  von  Druckanderungen  bei 
verschiedenen  Geschwindigkeiten,"  Philosophische  Studien,  Vol.  XII, 
p.  531.  The  average  threshold  for  increase  for  lOO  grammes  was  there 
found  to  be  2.5  grammes. 

An  additional  illustration  of  a  difference  in  sensations  that  is  real 
but  imperceptible  could  be  found  in  the  fact  that  the  difference  between 
two  successive  impressions  becomes  clear  when  we  shorten  up  the 
time-interval  between  them,  although  with  a  longer  interval  the  two 
impressions  seem  identical.  The  mere  change  of  the  interval  cannot 
be  supposed  to  produce  the  difference  of  intensity;  it  merely  makes  it 
apparent  to  us  by  allowing  the  comparison  to  be  more  exact.  With 
the  longer  interval  between  the  impressions,  there  is  consequently  a 
real  difference  that  we  cannot  perceive. 


86 


Experimental  Psychology 


No  assump- 
tion here  as 
to  the  rela- 
tion of  ner- 
vous to 
mental 
action. 


The  "  abso- 
lute "and  the 
"  discrimina- 
tive" thresh- 
olds are  iden- 
tical. 


to  sight,  hearing,  temperature,  pain,  and  the  like. 
Unaided  self-observation  might  lead  one  to  acknowl- 
edge here  only  considerable  differences  without  inter- 
mediate steps.  But  the  experimental  evidence  goes  to 
show  that  nature  makes  no  leaps.  In  all  these  fields 
there  are  infinite  gradations  of  intensity  and  also  of 
quality  that  are  real,  although  they  entirely  escape 
our  observation.  They  are,  to  use  Leibnitz's  phrase, 
petites  perceptions^  of  whose  existence  immediate  in- 
trospection gives  no  hint.  Such  facts  as  these  seem 
to  me  to  compel  us  to  admit  that  the  mind  is  wider  1 
than  the  portions  we  can  directly  perceive.  And  the 
great  advantage  of  such  evidences  as  these  is,  that 
they  do  not  require  some  questionable  assumption 
such  as  that  there  is  a  complete  analogy  between 
mind  and  brain,  or  that  stimulus  and  sensation  run 
exactly  parallel  courses.  All  this  is  left  an  open 
question,  and  the  decision  of  it  either  way  does  not 
affect  the  present  evidence  in  the  least. 

From  the  position  thus  gained  we  may  return  to 
the  question  of  subliminal  sensations,  and  point  out 
more  clearly  what  the  probabilities  are. 

The  reader  will  recall  the  two  kinds  of  threshold 
mentioned  some  moments  ago,  — the  threshold  where 
a  sensation  fades  completely  away,  and  the  thresh-, 
old  where  two  impressions,  although  clear  and 
strong,  cease  to  be  distinguishable.  It  is  customary 
in  psychology  to  draw  a  sharp  line  between  these 
two  kinds  of  phenomena,  and  to  say  that  the  disap- 
pearance of  a  sensation  is  quite  different  from  the 
fading  out  of  a  difference  between  two  sensations. 
In  all  probability,  however,  this  is  a  mistake,  and  the 


Further  Considerations  87 

two  facts  spring  from  the  same  source.  The  point 
at  which  a  diminishing  sensation  seems  to  die  away 
is  probably  not  where  its  intensity  becomes  zero,  but 
is  merely  the  point  at  which  it  is  no  longer  distinguish- 
able from  the  nebulous  background  of  sensations 
that  are  always  with  us.  A  particular  impression 
must  have  a  certain  appreciable  strength  of  its  own 
to  cause  it  to  stand  out  from  this  dim  confusion, 
arising  in  part  from  the  mere  circulation  of  the  blood 
in  the  various  organs  of  sense.  The  low  murmur  of 
life,  as  from  a  great  city,  is  always  within  us,  and  a 
weak  sensation  may  be  lost  from  view  merely  because 
it  is  not  sufficiently  different  from  the  host  of  other 
weak  sensations  present  at  the  same  time.  As  fur- 
ther experimental  evidence  which  directly  favors  this 
view,  we  find  by  actual  test  that  all  sensations  feel 
more  and  more  alike  the  weaker  they  are.  A  person 
blindfolded  cannot  unerringly  distinguish  between  the 
soft  contact  of  wool  and  a  gentle  glow  of  warmth  near 
the  skin.i  And  careful  observers  will  not  infrequently 
be  in  doubt  whether  an  exceedingly  minute  change 
of  pressure  on  the  skin  is  of  sound  or  of  touch.^  It 
seems  probable  therefore  that  what  we  call  the  abso- 
lute threshold  —  where  sensations  seem  to  fade  away 
—  is  but  a  special  case  of  the  general  fact  that 
differences  must  be  of  a  certain  amount  before  we 

1  See  Moleschott's  Untersuchimgen  zur  Naturlehre,  etc.,  Vol.  VIII, 
p.  393,  where  Fick  reports  Wunderli's  original  experiments.  His  obser- 
vations are  readily  verified. 

^  This  I  have  found  to  be  the  case  with  several  good  subjects  when 
a  slight  noise  occurred  at  the  moment  when  a  barely  perceptible  change 
of  pressure  was  expected.  See  "  Ueber  die  Wahrnehmung,"  etc., 
Philosophische  Studien,  Vol.  XII,  p.  547. 


88 


Experimental  Psychology 


The  exist- 
ence of  im- 
perceptible 
sensations 
now  seems 
better  sup- 
ported. 


Direct  evi- 
dence of 
their  exist- 
ence and 
force. 


Effect  of 

unseen 

shadows. 


'  can  perceive  them.  A  pressure  or  any  other  experi- 
ence must  possess  some  appreciable  intensity  if  we 
are  to  recognize  it  in  the  chaos  of  other  sensations  so 
like  it.  As  soon  as  we  can  no  longer  discern  it  we 
feel  that  it  is  gone,  but  in  truth  it  may  still  exist 
through  many  degrees  of  strength  before  it  utterly 
passes  from  the  mind.  The  limit  to  our  power  of 
distinguishing  differences,  taken  in  connection  with 
the  general  similarity  of  weak  sensations,  leads  one 
consequently  to  beheve  that  these  simpler  mental 
processes  do  actually  descend  to  a  low  and  dim 
region  where  introspection  cannot  follow  them. 
They  are  subliminal,  and  yet  they  are  still  in  the 
mind.  Let  their  strength  be  still  further  reduced, 
and  they  cease  even  this  shadowy  life.  The  existence 
of  subconscious  sensations,  which  could  not  well  be 
inferred  from  the  fact  of  subliminal  stimulations,  thus 
appears  quite  reasonable  when  approached  from  the 
side  of  these  imperceptible  differences. 

But  if  this  were  all,  there  would  perhaps  be  a 
certain  theoretical  interest  in  the  fact  that  experience 
could  exist  at  so  low  an  ebb,  but  we  might  be  inclined 
to  believe  that  the  existence  of  imperceptible  phe- 
nomena was  of  no  importance  for  our  mental  life.  The 
experimental  work  goes  to  show,  however,  that  these 
obscure  and  even  imperceptible  variations  are  impor- 
tant factors  in  processes  which  we  can  perceive.  They 
affect  the  action  from  behind  the  scenes.     Our  con- 

I  scious  space-perception,  for  instance,  may  be  altered 
by  these  utterly  elusive  elements.  Some  recent  ex- 
periments by  Dunlap  show  that  lines  so  drawn  as 
to  produce  an  illusion  of  distance,  may  influence  our 


Further  Considerations  89 

estimate   of   space   even  when  these  lines  are  quite 
imperceptible.^     In  the  M tiller- Lyer  diagram,  shown 
in  Fig.   10,  the  small  angles  on  the  horizontal  line 
make  the  two  halves  seem  of  different  length.     In  1 
the  experiment  mentioned,  such  a  horizontal  line  was 

^-^ < 

Fig.  10.  —  The  Miiller-Lyer  figure. 

distinctly  visible  with  its  segments  marked  by  short 
cross-lines  (Fig.  11);  the  small  angles  of  the  Miiller- 
Lyer  figure,  however,  were  made  by  shadows  from  a 
light  so  faint  that  the  observer  could  not  tell  whether 


Fig.  II.  —  The  dotted  lines  show  the  different  arrangements  of  shadows 
that  — even  when  they  are  invisible  —  continue  to  influence  one's 
judgment. 

the  angles  were  thrown  as  in  A  or  as  in  B  of  this 
figure,  nor  whether  in  fact  any  angles  were  thrown 
upon  the  line.  And  yet  under  these  circumstances 
the  run  of  judgments  in  a  long  series  of  experiments 

1  Dunlap,  "  The  Effect  of  Imperceptible  Shadows  on  the  Judgment 
of  Distance,"  Psychological  Review^  Vol.  VII,  p.  435. 


90  Experimental  Psychology 

I  indicated  that  the  apparent  length  of  the  segments 
\  was  altered  according  as  these  subliminal  shadows 
1  were  cast  in  the  one  way  or  the  other,  or  (unknown 
\  to  the  observer)  were  not  cast  upon  the  line  at  all. 
Experiments  A  further  and  final  example  might  be  drawn  from 
bie^soundl''  '  ^^^  ^^^^^  ^^  sounds  upon  the  attention.  We  have  all 
had  our  attention  caught  by  the  sudden  stopping  of 
a  clock,  although  we  could  not  otherwise  have  told 
whether  it  had  been  ticking  or  not.  It  may  be  that  in 
this  case  we  are  conscious  of  the  beats,  but  are  simply 
more  attentive  to  other  things.  But  under  different 
conditions  the  facts  seem  somewhat  less  ambiguous. 
Suppose  a  person  is  in  a  silent  room  listening  in- 
tently to  a  low  sound  in  a  telephone,  growing  fainter 
and  fainter,  after  the  manner  already  described 
(p.  79),  until  finally  he  is  unable  to  hear  it,  strain  his 
ears  as  he  may.  Yet  even  when  the  observer  is  posi- 
tive that  he  has  lost  the  sound,  if  the  imperceptible 
note  be  cut  off  completely,  the  subject  will  often 
notice  the  change.  A  void  suddenly  opens  up  in  the 
auditory  field  which  had  already  appeared  a  perfect 
blank.  At  other  times,  when  the  subliminal  sound  is 
cut  off,  what  we  are  struck  by  is  not  so  much  the  dis- 
appearance of  the  sensation  itself,  but,  rather,  a  sud- 
den and  subtle  change  of  mood  —  a  feeling  of  relief, 
as  if  the  attention  could  now  be  honorably  recalled, 
since  the  tenuous  nothing  for  which  it  had  been 
searching  had  been  definitely  reported  dead.  If  this 
correctly  describes  the  mental  state,  what  we  feel 
under  these  particular  circumstances  is  not  the  de- 
parture of  the  sound  itself,  but  a  conscious  effect  of 
that  departure,  a  sudden  unaccountable  relief.      It 


Further  Considerations  91 

would  imply  that  the  sound,  imperceptible  though  it 
was,  could  still  muster  up  strength  to  tease  and  elude 
the  attention,  until  the  actual  stopping  of  the  sound  | 
brought  the  strain  to  an  end.  There  is,  of  course, 
nothing  decisive  in  this  alone ;  it  might  be  explained 
without  assuming  that  the  sound  was  there  at  all. 
For  it  is  not  always  necessary  to  have  a  present 
experience  of  a  thing  in  order  to  note  its  departure. 
Its  mere  physical  presence  may  produce  a  condition 
of  nervous  equiUbrium  for  which  there  is  no  positive 
psychic  counterpart,  while  its  sudden  interruption 
might  disturb  this  status  quo  sufficiently  to  give  a 
slight  but  positive  mental  shock.  But  on  the  whole 
the  explanation  I  have  suggested  seems  to  me  the 
more  probable,  and  so  I  offer  the  experiment  as 
supporting  the  doctrine  of  imperceptible  mental 
events. 

And  as  in  this  case,  so  I  might  say  of  all  the  evi-  Character  of 
dence  offered,  —  that  alternative  explanations  are  pos-  a^^^whoie^^ 
sible.  Brain-processes  or  mental  facts  may  yet  be  dis- 
covered which  would  put  all  our  evidence  in  another 
light.  And  to  entertain  even  the  possibility  of  other 
explanations  has  a  certain  value ;  it  serves  as  an  en- 
courager  of  hesitancy,  and  brings  one  to  his  senses 
who  would  claim  that  he  can  demonstrate  the  case. 
He  may  flout  the  alternatives  as  he  pleases ;  but  if 
there  is  an  alternative  even  of  the  most  improbable 
sort,  he  must  change  his  tone  from  absolute  proof  to 
preference  and  probability.  So  that  the  facts  I  have 
presented  are  given  with  the  feeling  that  they  are 
gently  persuasive  merely ;  they  invite  rather  than 
compel  our  belief. 


92  Experimental  Psychology 

Concluding  What  sccms  to  me  the  meaning  of  these  evidences 
tfoTorthe  ^^  perhaps  already  clear.  They  lead  us  to  a  mean  be- 
resuits.  tween  two  indefensible  extremes.     On  the  one  side 

is  the  teaching  that  all  the  events  in  the  mind  occur 
\  in  full  light,  and  that  the  natural  history  of  the  mind 
must  confine  itself  to  those  occurrences  which  a  trained 
introspection  can  report.  Experimental  results,  how- 
ever, draw  us  away  from  such  a  view ;  they  show  us 
that  it  cramps  the  facts.  At  the  same  time  they  do 
not  carry  us  to  the  opposite  extreme  —  that  of  uncon- 
scious ideas  as  so  often  understood.  That  is  a  mystic 
doctrine  according  to  which  we  each  have  an  un- 
visited  psychological  lumber  room  (to  use  Mr.  Pod- 
more's  expression),  with  its  accumulation  of  forgotten 
experiences,  a  room  which,  though  unvisited  by  our  con- 
scious self,  is  occupied  by  an  unconscious  self,  busied 
with  all  manner  of  unconscious  devices  to  accomplish 
unconscious  ends :  getting  subliminal  pleasures  and 
disappointments  out  of  its  quiet,  subliminal  life.  Here 
the  unconscious  mental  life  is  conceived  as  filled  with 
much  the  same  kind  of  things  as  is  our  conscious  life, 
the  difference  being  that  it  is  unconscious.  Our  re- 
searches lead  us  into  no  such  extravagance  as  this. 
The  results  are  not  in  favor  of  unconscious  ideas, 
but  rather  of  certain  unconscious  materials  out  of 
[which  conscious  ideas  arise.  They  lead  us  to  ac- 
knowledge that  there  are  indiscernible  occurrences 
in  the  mind  of  a  very  definite  and  non-mythical  char- 
acter, comings  and  goings  of  dim  sensations,  subtle 
variations  in  the  strength  and  quality  of  certain  con- 
stituents, which,  minute  and  imperceptible  though 
they  be,  are  sufficient  to  destroy  the  equilibrium  and 


Further  Considerations  93 

produce  a  transformation  of  the  whole  mental  state. 
The  experiments,  though  they  carry  us  to  no  extremes, 
do  open  up  a  new  and  most  attractive  field  of  research. 
They  assure  us  that  we  can  go  a  little  below  the  sur-z 
face,  a  little  into  the  shadows  of  our  experience. 

And  now  a  word  as  to  James's  indictment^  that  all  Nodangerto 
this  is  the  "  sovereign  means  for  believing  what  one  ^.^m^t^^e  un- 
Hkes  in  psychology,  and  of  turning  what  might  be-  conscious 
come  a  science  into  a  tumbling-ground  for  whimsies." 
One  must  acknowledge  that  there  is  a  certain  his- 
torical justification  for  James's  remark.  The  doctrine 
of  imperceptible  phenomena  to-day  keeps  bad  com- 
pany ;  it  seems  to  have  an  affinity  for  minds  that 
throw  logic  and  the  canons  of  induction  to  the  winds. 
But  we  must  beware  of  psychological  exclusiveness, 
and  not  reject  a  truth  because  we  feel  aversion 
toward  the  kind  of  men  who  most  readily  accept  it.  ^ 
And,  after  all,  there  is  nothing  more  anarchic 
in  this  doctrine  than  in  the  notion  that  the  phys- 
ical world  has  its  imperceptible  events.  What  a 
tumbling-ground  for  whimsies  the  recognition  of  an 
invisible  energy  Hke  electricity  or  magnetism  has 
supplied  !  Only  some  weeks  ago  a  deluded  mortal 
was  expounding  to  me  how  insanity  could  be  drawn 
off  from  one  person  and  injected  into  another  by 
means  of  magnets.  But  one  does  not  on  this  account 
feel  that  scientific  procedure  is  at  an  end,  once  we 
admit  what  leads  to  such  vagaries.  Dreaming  and 
knowing  are  as  distinct  after  such  admissions  as  be- 

1  See  p.  67.  Professor  James  in  his  subsequent  work  has  become 
more  friendly  to  the  unconscious.  Cf.  e.g.  his  Varieties  of  Religious 
Experience,  1902,  pp.  233  et  seq. 


94  Experimental  Psychology 

provided  the  f orc.  Bccausc  immediate  sensible  confirmation  is  dis- 
attitudeli  pensed  with,  we  need  not  think  that  all  the  ordinary 
regard  to  the  rules  of  evidence  are  abrogated  and  that  we  are  free 
mafnta^ned^  to  believe  what  we  please.  There  must  still  be  sen- 
jSible  evidence  for  whatever  is  proposed  in  this  field; 
but  since  the  evidence  must  now  be  circumstantial, 
rather  than  direct,  all  the  more  need  of  putting  it 
mercilessly  to  the  test,  of  holding  before  ourselves 
alternative  explanations,  of  weighing  and  sifting  until 
we  can  convince  ourselves  that  there  is  more  reason 
to  believe  that  some  unseen  factor  is  at  work  than 
that  the  causes  of  the  phenomena  are  among  the 
events  we  can  observe.  Neither  credulity  nor  hard- 
ened unbelief  will  serve  us  here ;  we  must  demand 
the  evidences,  but  respect  them  when  they  come. 
Such  an  attitude  seems  hardly  to  endanger  the  prog- 
ress of  psychology,  but  rather  gives  an  added  assur- 
ance that  the  study  will  progress. 


CHAPTER  VI 
ILLUSIONS  AND   THEIR  SIGNIFICANCE 

Our  illusions  of  perception  seem  contrived  for  the  illusions  are 
special  purposes  of  psychology,  —  as  if  Providence,  service  to ^the 
foreseeing  the  natural  perplexity  of  the  student  of  psychologist, 
mind,  had  sent  them  for  his  comfort.  For  nothing 
else  reveals  as  they  do  the  manner  of  the  mind's 
activity.  As  long  as  our  mental  operation  is  perfect, 
and  does  not  color  or  distort  the  facts,  the  mind  is 
like  some  subtle  medium  that  permits  us  to  see  all 
things,  while  remaining  itself  unseen.  But  when  once 
the  mind's  action  becomes  troubled  so  that  it  tinges 
and  deforms  the  scene,  then  our  psychic  processes 
themselves  come  to  view  and  we  are  enabled  to  note 
their  form.  For  psychological  purposes,  therefore, 
illusions  might  perhaps  be  compared  to  the  deli- 
cate, artificial  stains  which  are  of  such  help  to  those 
who  use  the  microscope;  the  dyes  discolor  the  object 
and  render  it  in  a  way  untrue ;  but  only  to  bring 
out  with  tenfold  clearness  the  hidden  niceties  of  its 
structure. 

For  this  reason  the  study  of  illusions  occupies  a 
prominent  place  in  psychological  work.  Whatever 
may  be  one's  field  of  investigation,  he  must  constantly 
attend  to  the  illusions  there ;  and  not  with  a  purely 
negative  and  hostile  attitude  toward  them,  as  might 

95 


96 


Experimental  Psychology 


Their  range 
and  provi- 
sional classi- 
fication. 


I.  Illusions 
from  spon- 
taneous sen- 
sations. 


perhaps  be  supposed  -^  as  if  an  experimenter  wished 
to  find  them  only  in  order  to  avoid  them  and  free  his 
results  from  error ;  but  rather  does  he  welcome  them 
as  of  positive  service  in  throwing  light  on  the  prob- 
lem in  hand. 

It  is  difficult  to  find  a  field  of  research  where 
these  distortions  of  reality  do  not  occur.  Our  sense- 
perceptions —  taste,  touch,  hearing,  sight  —  are  pro- 
verbially fallible.  But  they  are  by  no  means  alone 
in  this.  Self-observation,  also,  gives  us  appearances 
opposed  to  the  facts ;  there  are  errors  in  our  estimate 
of  time;  and  memory  inserts  into  the  past  various 
items  that  never  occurred,  or  transposes  the  order  of 
actual  events.  So  that  one  is  embarrassed  by  the 
very  wealth  of  the  materials  here,  and  is  forced  to 
make  an  unusually  exclusive  selection  to  illustrate  the 
more  significant  features  of  the  subject. 

For  the  purpose  in  hand  it  will  perhaps  be  best  not 
to  group  illusions,  as  is  frequently  done,  according  to 
the  special  field  in  which  they  occur,  as  illusions  of 
sight  or  of  touch  or  of  introspection  or  of  memory ; 
but  according  to  the  general  causes  which  produce 
them.  Judged  by  the  broader  circumstances  under 
which  they  arise,  there  are  three  provisional  classes 
into  which  illusions  may  be  grouped. 

In  the  first  class  we  should  include  those  illusions 
which  arise  from  a  certain  perversity  of  the  sense- 
organs  in  that  they  give  us  sensations  by  spontaneous 
action,  not  waiting  for  an  excitation  to  come  in  from 
the  outer  world.  Such  is  that  subjective  ringing  in  the 
ears  which  we  sometimes  hear,  and  perhaps  also 
the  faint  mist  which  our  eyes  always  give  us  even 


Illusions  and  their  Significance  97 

when  in  the  darkest  room,  although  this  may  be  in 
large  part  due  to  an  action  of  the  brain.  The  visual 
field  is  never  free  from  vague  forms  and  colors  not 
due  to  outer  things  —  forms  which  persist  in  our  sleep, 
and  doubtless  furnish  much  of  the  stuff  our  dreams 
are  made  of.  In  the  case  of  the  delirious  and  the 
insane,  such  images  are  possibly  more  intense,  and 
when  decked  out  by  the  morbid  fancy,  become  the 
strange  realities  which  people  their  world. 

Into  this  class  fall  also  many  of  our  illusory  contrast 
effects  and  complementary  after-images.  In  the  eye, 
the  stimulus  falling  on  a  particular  place  of  the  retina 
produces  a  temporary  disturbance  of  the  functions  of 
neighboring  parts;  and  even  after  it  has  ceased  to 
play  upon  the  nervous  surface  of  the  eye,  some  time 
is  required  before  a  perfect  equilibrium  is  again  re- 
stored. This  is  perhaps  the  cause  of  that  illusion  of 
motion  we  get  after  looking  at  a  spiral  like  the  accom- 
panying one  (Fig.  12),  made  to  revolve  at  a  moderate 
speed ;  when  the  spiral  is  stopped  it  seems  gradually 
to  draw  in  or  expand  —  there  is  a  viscid  flow  in  a 
direction  opposed  to  the  original  movement  that  the 
spiral  seemed  to  have  as  the  figure  revolved.  The 
same  thing  occurs  if  we  look  over  the  side  of  a  mov- 
ing ship  at  the  water  rushing  by ;  the  deck  will  then 
seem  to  glide  slowly  toward  the  bow  of  the  vessel, 
or  if  we  look  long  at  a  waterfall  and  then  away  to  the 
cliffs,  these  move  gradually  skyward.  It  seems  clear 
that  all  these  illusions  depend  in  the  main  on  some 
disturbance  in  the  sense-organ,  an  unusual  behavior 
of  the  eyes  or  ears  in  these  cases  is  at  the  bottom  of 
the  abnormal  experience. 


98  Experimental  Psychology 

Let  us  now  pass  to  some  examples  of  illusions 
which  offer  a  certain  contrast  to  those  we  have  just 
been  considering. 
II.  Illusions  If  two  equal  weights  —  each,  say,  50  grammes  —  be 
att^tioT^°^  concealed  in  boxes  of  quite  different  size,  the  weight 
in  the  large  box  will  seem,  when  lifted,  much  lighter 
than  that  in  the  smaller  box.  And  the  amount  of 
the  illusory  effect  can  be  measured ;  we  may  gradu- 
ally add  to  the  weight  in  the  larger  box  or  take  from 
that  in  the  smaller  one,  until  the  two  seem  equal ; 
the  addition  or  subtraction  thus  required  to  bring 
them  to  apparent  equality  gives  us  some  idea  of  the 
strength  of  the  illusion.  In  the  case  of  boxes  having 
the  relative  sizes  given  in  the  diagram  (Fig.  13),  I  have 

often    found   that 

the  weight  of  the 
smaller  box  must 
be     reduced      by 


::i 


YiQ^  13.  as    much    as     15 

grammes  before  it 
will  seem  equal  in  weight  to  the  50  grammes  having 
the  larger  volume.  The  illusion  starts  from  the  expec- 
tation which  the  sizes  of  the  boxes  arouse.  Experience 
has  taught  us  that  in  general  the  weights  of  things 
increase  with  their  volume.  But  the  actual  weight  of 
the  larger  box  is  so  much  less  than  we  anticipated, 
and  so  much  less  than  we  had  prepared  our  hand  to 
raise,  that  by  contrast  it  seems  much  Ughter  than  it 
otherwise  would.  It  is  underestimated,  and  for  like 
reasons  the  weight  in  the  smaller  box  is  overestimated. 
A  further  illusion  of  similar  psychological  import  is 
found  in  comparing  the  intensities  of  a  number  of 


Illusions  and  their  Significance  99 

sounds  coming  in  quick  succession.  When  we  listen 
to  such  a  rapid  series,  say  of  clicks  that  are  of  equal 
strength,  if  they  come  neither  too  fast  nor  too  slow, 
most  persons  cannot  actually  hear  them  as  equal. 
Certain  regularly  recurring  members  seem  sHghtly 
more  emphatic  than  the  rest,  and  the  whole  series 
falls  into  a  subjective  rhythm.  We  can  interrupt  this 
periodic  emphasis  and  make  it  rest  now  here,  now 
there,  but  fall  somewhere  it  must ;  the  attention  must 
glide  over  some  beats  and  linger  on  others,  and  this 
subjective  selection  somehow  tricks  us  into  a  momen- 
tary feeling  that  the  favored  impressions  are  the 
stronger. 

Under  other  circumstances  the  stress  of  attention, 
as  is  well  known,  deceives  us  in  our  estimate  of  time. 
A  stretch  of  blank  time  marked  off  by  an  initial  and 
a  final  stroke  does  not  seem  of  the  same  length  as  an 
identical  interval  filled  in  with  a  number  of  succes- 
sive strokes.  It  will  seem  longer  or  shorter  than  the 
"filled"  time,  according  to  the  actual  length  of  the 
time  with  which  we  are  dealing.  But  still  more 
striking  is  the  illusion  which  may  occur  as  to  the 
order  in  which  impressions  come.  If  we  observe  a 
rapid  sequence  of  colors  appearing  at  an  opening  in 
a  screen,  and  a  stroke  of  a  bell  be  given  in  conjunc- 
tion with  some  single  one  of  them,  say,  green,  the 
place  in  the  color  series  where  the  stroke  seems  to 
occur  is  usually  not  its  true  place  in  the  series.  We 
ordinarily  locate  the  sound  much  too  early  in  the 
series ;  it  will  seem  to  come,  perhaps,  with  a  blue  or 
a  yellow  that  preceded  the  green.  Why  we  should 
do  this  is  not  entirely  clear ;  the  displacement  is  too 


lOO 


Experimental  Psychology 


These  are 
not  ex- 
plained by 
"experi- 
ence." 


They  show 
the  interplay 
of  mental 
processes. 


large  to  be  accounted  for  by  the  lag  in  the  photo- 
chemical process  of  the  eye,  so  that  the  illusion  is 
•  probably  due  to  the  unequal  attention  we  give  to  the 
different  members  of  the  series.  Our  greater  atten- 
tion to  the  sound  seems  to  crowd  aside  the  colors 
which  appear  at  about  the  same  time;  the  stress 
upon  the  bell  stroke  gives  it  a  prominence  and  tem- 
poral promotion  over  some  of  the  colors,  which  for  an 
instant  are  less  attended  to  and  consequently  suffer 
a  kind  of  eclipse. 

Phenomena  of  this  kind  do  not  spring  from  the 
sense-organs,  nor  can  they  be  fully  explained  by  ap- 
pealing to  habit  or  custom  or  "  experience."  Experi- 
ence has  not  taught  us  that  in  the  majority  of  cases 
sounds  come  early  in  a  color  series,  or  that  succes- 
sive sounds  really  are  due  to  causes  which  show  a 
rhythmic  rise  and  fall  of  energy  ;  nor  has  experience 
taught  us  that  large  bodies  are  usually  lighter  than 
small  ones,  but  more  often  the  reverse.  These  illu- 
sions, therefore,  reveal  a  mental  activity  to  some 
extent  independent  of  mere  custom  brought  about 
by  experience ;  they  show  that  our  mental  processes 
interplay  and  modify  one  another  —  that  our  esti- 
mate of  time,  for  instance,  or  our  feeling  of  the 
intensity  of  a  pressure  or  a  sound  is  neither  imposed 
upon  us  by  sheer  force  of  the  outer  facts ;  nor  is  it, 
on  the  other  hand,  the  result  of  a  special  and  isolated 
psychic  process  whose  only  function  is  to  mark  the 
time  or  to  perceive  weight  or  sound.  Men  used  to 
believe  in  a  number  of  independent  activities  of 
mind.  We  had  many  separate  faculties  working  like 
separate  organs  in  the  body,  —  a  faculty  of  sight. 


Illusions  and  their  Significance  loi 

another  of  touch,  of  memory,  of  judgment,  of  atten- 
tion, and  so  on,  —  a  view  well  represented  in  the  old 
phrenology,  where  a  special  brain-tract  was  given 
over  to  the  exclusive  use  of  each  of  a  score  of  psychic 
activities,  from  smell  to  "  philoprogenitiveness  "  and 
reverence.  Illusions  show,  on  the  contrary,  how 
closely  interlaced,  how  interdependent,  our  mental 
activities  are;  the  errors  spring  from  an  intimatei 
interplay  of  sensation  and  memory  and  attention  and! 
judgment.  Our  mental  stress,  our  attention,  our 
feeling  of  value,  can  cause  the  temporal  order  to  be 
reversed ;  there  is,  then,  no  sense  of  time  in  which 
attention  and  interest  play  no  part.  The  weight-size 
illusion  also  shows  how  the  different  sides  of  mind 
conspire :  expectation  and  images  called  up  from  pre- 
vious experience  here  crowd  in  upon  the  actual  sen- 
sations, but  instead  of  being  able  to  make  these 
sensations  appear  like  themselves,  they  make  them 
take  on  an  entirely  contrasting  aspect.  And  the  same 
occurs  in  the  rhythm  of  equal  sounds ;  the  intensity 
is  affected  by  our  subjective  attitude  toward  them ; 
they  are  caught  up  and  impressed  by  the  general  Evensensa- 
state  of  the  mind.  No  sensation  has  an  inviolate  Jh°"J*harac- 
inner  character  which  remains  unaffected  by  the  ■  ter  from  their 
larger  mental  Hfe.  The  connection,  the  significance  Jfjf"*^^  ^^*' 
of  impressions  alters  their  very  essence.  The  quality 
of  the  voice  sounds  different  when  we  cannot  under- 
stand what  is  said ;  and  colors  in  the  face  or  in  the 
landscape  come  out  with  surprising  freshness  if  we 
see  them  reflected  in  a  distorting  glass  or  metal,  or 
look  at  the  scene  with  head  bent,  so  that  the  recog- 
nition of  objects  is  in  some  degree  disturbed.     The 


I02 


Experimental  Psychology 


meaning  of  sensations  changes  their  pure  sensa- 
tion quality.  Each  process  is  what  it  is  because 
other  things  are  what  they  are ;  here,  too,  nothing  is 
fair  or  good  alone.  The  fiction  of  independent  sensa- 
tions which  by  association  make  up  our  perceptions 
and  ideas,  the  fiction  of  a  number  of  separate 
faculties  each  with  its  exclusive  field,  —  these  go  the 
way  of  the  similar  fictions  in  physics  or  political 
science,  —  the  belief  in  a  world  constituted  of  inde- 
pendent atoms,  or  in  a  sovereign  state  arising  by 
contract  of  free  and  independent  persons. 


III.  Illu- 
sions due  to 
fixity  of  inter- 
pretation, or 
"  custom." 


The  final  group  of  illusions  would  include,  per- 
haps, the  great  mass  of  our  familiar  deceptive  expe- 
riences: the  change  in  the  apparent  distance  of  objects 
from  us  as  the  atmosphere  changes  in  clearness,  the 
vivid  appearance  of  depth  which  the  stereoscope 
gives,  the  circling  of  things  about  us  when  we  are 
dizzy,  the  car-window  illusion  which  makes  our  train 
seem  to  be  in  motion  when  a  train  beside  us  begins  to 
move  —  all  these  and  a  hundred  more  have  a  certain 
common  origin.  These  illusions,  unlike  the  group 
just  considered,  are  due  to  mental  habit  or  custom, 
are  due  to  the  particular  training  which  experience 
has  given  us;  and,  having  once  learned  our  lesson, 
we  proceed  to  apply  it  with  mechanical  regularity,  in 
season  and  out  of  season.  We  stick  to  the  mode  of 
mental  activity  which  we  have  found  appropriate  to 
the  general  run  of  cases.  Thus  ninety-nine  times  out 
of  a  hundred  we  find  that  the  movement  of  the  whole 
field  of  view  from  a  car  window  is  due  to  the  motion 
of  the  car  itself ;  the  habit  of  interpreting  this  expe- 


Fig.  14.  — Aristotle's  Illusion. 


Fig.  15.  —  Diagram  to  represent  the 
psychological  effect  of  the  con- 
tacts in  Fig.  14. 


Fig.  17.  —  The  converse  of  Aristotle's 
Illusion.     First  form. 


Fig.  18.  —  Diagram  of  the  psychologi- 
cal effect  of  the  contacts  in  Fig.  17. 


Fig.  19.  —  The  converse  of  Aristotle's 
Illusion.    Second  form. 


Fig.  20.  —  Diagram  of  the  psychologi- 
cal effect  of  the  contacts  in  Fig.  19. 


Illusions  and  their  Significance  103 

rience  becomes  fixed,  and  thenceforth  all  movements 
of  the  whole  field  mean  for  us  but  this  one  thing, 
whether  they'  actually  arise  from  our  movement  or 
not.  If  the  more  usual  way  in  travelling  had  been 
to  sit  still  at  a  window  and  have  something  move  the 
landscape  outside  until  the  right  portion  of  the  earth 
arrived,  our  illusion  would  have  been  the  reverse; 
an  actual  motion  of  the  car  would  then  have  felt 
like  a  movement  of  things  outside  our  window. 

An  excellent  example  of  illusions  of  this  class,  and  Aristotle's 
one,  moreover,  which  permits  of  experimental. varia-  -Jg^con^erse 
tion  and  reversal,  is  the  familiar  deception  of  touch, 
called  Aristotle's  illusion.  If  the  index  and  second 
finger  of  the  same  hand  be  crossed  and  a  pencil  be 
placed  between  their  tips,  as  in  Fig.  14,  we  feel  two 
pencils  there  instead  of  one.  Here,  again,  the  cause 
is  found  to  lie  in  long  training  and  mental  habit. 
The  parts  of  our  fingers  with  which  the  pencil  is  in 
contact  can  usually  be  touched  only  by  two  separate 
objects  with  the  two  fingers  lying  between.  The 
tactile  impressions,  being  such  as  are  customarily 
caused  by  two  objects,  are  by  force  of  habit  inter- 
preted as  two  (somewhat  as  in  Fig.  15),  although  a 
single  object  is  now  the  cause. 

It  is  especially  interesting  that  the  converse  of  this 
illusion  is  also  true ;  namely,  that  an  impression  which 
is  habitually  due  to  a  single  object  will  be  felt  as  a 
single  object,  even  when,  from  the  unnatural  position 
of  the  fingers,  it  is  now  produced  by  two  objects  quite 
a  distance  apart.  If  two  prongs  of  flexible  wood  or 
of  wire  be  attached  to  a  handle  so  that  they  can 
be  manipulated  together  (Fig.   16),  and  they  be  so 


C=o 


104  Experimental  Psychology 

adjusted  that  the  crossed  fingers  lie  between  them 
and  yet  in  contact  with  them  both,  as  in  Fig.  17, 
places  on  the  skin  can  now  be  found  which  absolutely 
destroy  the  feeling  of  distance  between  the  prongs ; 

they  merge  into  one,  and 
are  felt  as  a  thin  strip 
running  up  between  the 
crossed  fingers  (Fig.  18). 
Or  again,  if  we  move  the  two  prongs  to  points  on  the 
skin  which  normally  require  three  separate  things  to 
touch  them  at  once,  as  in  Fig.  19,  the  two  strips  are 
now  felt  as  three  (Fig.  20).  The  single  principle 
holds  throughout  this  varied  illusion,  that  we  inter- 
pret the  impressions  according  to  the  causes  which 
I  normally  produce  them.  The  sensations  which  usu- 
ally come  from  a  single  object  are  felt  as  a  single 
object:  the  impressions  which  usually  come  from 
two  objects  are  felt  as  two  objects,  however  these 
impressions  or  sensations  may,  under  exceptional 
circumstances,  be  produced.  In  this  entire  class  of 
illusions,  therefore,  there  is  clearly  present  a  process 
of  interpretation y  and  the  mode  of  interpretation  which 
we  adopt  for  all  cases  is  that  which  experience  has 
'  taught  us  is  generally  correct.  The  illusions  them- 
selves arise  because  of  exceptional  cases  not  provided 
for  in  our  general  rule  of  interpretation.  By  sheer 
mental  inertia  we  continue  to  interpret  the  exceptional 
cases  as  if  they  were  regular,  and  so  we  go  astray. 
Light  on  Nothing  could  better  illustrate  the  way  our  minds 

normal  per-  ^^^grk,  not  Only  Under  exceptional  circumstances,  but 
also  under  ordinary  conditions.  Our  illusions  make 
clear  the   process  of  perception   itself ;   they  show 


Illusions  and  their  Significance  105 

how  we  perceive  the  outer  world  even  when  we  per- 
ceive it  correctly.  We  do  not  stand  face  to  face  with 
the  outer  facts  and  passively  receive  their  accurate 
image.  There  is  no  direct  and  absolutely  reliable 
intuition  of  things  without.  The  world  merely  gives 
us  §^-tuccession  of  impressions  which  of  themselves  | 
have  no  single  and  inevitable  meaning.  Our  sen- 
sations are  more  or  less  arbitrary  symbols  of  the 
outer  facts,  and  we  must  learn  to  read  them.  To  The  outer 
use  Berkeley's   fierure,  our   sense-impressions   are  a  ^?^^^  speaks 

•^  °  ^  a  language 

language ;  and,  like  any  language,,  they  must  be 
gradually  learned  and  are  never  entirely  free  from 
misunderstanding.  Many  of  the  signs  are  of  doubt- 
ful meaning,  and  we  must  judge  them  as  best  we 
can.  Here,  of  course,  training,  our  previous  experi- 
ence, our  temporary  preoccupation,  the  immediate 
surroundings  or  context,  are  what  determine  what  we 
shall  feel  to  be  true  in  the  particular  case.  But  with,  occa- 
nature  at  times  runs  counter  to  all  our  expectations.  u°"s^uaitura 
She  uses  a  familiar  expression  in  an  unusual  sense,  ofexpres- 
and  finds  us  totally  unprepared.  It  is  much  as  if 
some  laborer,  busied  in  a  watch  factory,  were  sud- 
denly to  rise  to  poetry  and  sing  the  praises  of  the 
spring ;  his  expression  "  spring "  would  produce  on 
the  minds  of  his  stolid  fellow-artisans  an  effect  analo- 
gous to  our  illusions  of  experience.  Their  own  par- 
ticular world  would  be  too  much  with  them,  so  that 
this  rare  and  unaccustomed  application  of  their  term 
would  be  misunderstood. 

Now,  in  spite  of  these  various  sources  of  illusion  — 
the  perversity  of  the  organs  of  sensation,  the  inter- 


sion. 


io6  Experimental  Psychology 

play  of  our  several  mental  processes,  and  the  inter- 
pretation of  exceptional  experiences  according  to  a 
habit  to  which  the  general  course  of  experience  has 
trained  us,  —  can  we  bring  all  these  different  causes 
under  one  common  principle  ? 

The  more  important  illusions  are  clearly  due  to 
errors  of  interpretation.  They  are  not  justly  to  be 
called  errors  of  sense ;  the  sensations  are  not  at 
fault,  nor  has  the  organ  of  sense  perverted  the  facts. 
The  symbols  or  signs  of  external  reality  have  simply 
been  misunderstood.  Here  the  illusions,  we  might 
say,  are  of  intellectual  rather  than  of  sensory  char- 
acter; if  we  could  arrive  at  their  right  meaning, 
no  illusion  would  occur.  But  in  two  of  the  classes 
of  deception,  the  symbols  themselves  do  not  seem 
to  be  misinterpreted;  they  have  been  distorted,  in 
the  one  case  by  the  nervous  organism,  and  in  the 
other  by  our  mental  stress.  These  illusions  conse- 
quently seem  to  stand  in  a  group  opposed  to  the 
others. 
The  three  And  yet  when  we  come  to  examine  them  closely, 

groups  of  ii-    ^g  ^g^^  ggg  ^j^^|.  there  is  no  fundamental  difference 

lusions  are 

fundamen-      here.     Even  the  illusions  that  seem  most  clearly  due 
tally  ahke.      ^^  scnse  are  actually  from  a  higher  source ;  and  if 
there  were  no   error   made  in  interpreting  the  im- 
pressions, the  mere  impressions  themselves,  whatever 
might  be  their  character,  could  never  produce   illu- 
sion.    Taken    by   themselves,   they   are    sensations, 
All  involve  a   neither  true   nor   false;   they  become  true  or  false 
t^tfon*^^'^^'    ^^^y  when  we  begin  to  view  them  as  signs  of  a  more 
permanent   reality.      If   we  could  keep  from  doing 
this,  if  we  could  keep  from  interpreting  them,  or  if, 


Illusions  and  their  Significance  107 

on  the  other  hand,  we  could  see  them  in  every  case 
in  their  proper  relations,  no  illusions  would  occur. 

The  difficulty  is  that  in  themselves  our  sensations 
tell  us  nothing  of  their  origin ;  they  stand  dumb 
before  us  and  leave  us  to  guess  their  secret.  But 
since  in  the  special  senses  more  of  the  sensory  impres- 
sions come  from  external  than  from  internal  causes, 
we  find  that  it  practically  works  best  to  fall  into  the 
habit  of  treating  them  all  as  from  without.  We  take 
the  course  which  suits  the  majority  of  cases,  and  so 
here,  again,  the  illusion,  even  when  it  belongs  to  the 
class  most  intimately  connected  with  the  organs  of 
sense,  is  at  bottom  due  to  custom  or  habit. 

We  can  conceive  of  two  kinds  of  worlds  in  which  Conceivable 
no  illusions  would  occur.     The  one  would  be  a  world  ^°'"^'^^.„ 

where  illu- 

in  which  every  impression  of  a  particular  sort  arose  sions  would 
from  one  set  of  causes  and  only  one.  Here  there  ^^1™^°*" 
would  be  no  ambiguity,  and  each  occurrence  would 
be  read  aright.  It  would  be  like  a  language  in  which 
every  word  was  always  used  in  an  unchanging  sense. 
The  other  equally  illusionless  world,  if  world  it  might 
be  called,  would  be  one  where  similar  impressions 
came  so  rarely  from  the  same  causes,  that  no  habit 
of  interpretation  could  ever  be  formed.  Alice's  Won- 
derland gives  some  hint  of  what  such  a  state  would 
be.  Each  experience  would  feel  like  an  absolutely 
unique  event ;  it  would  never  indicate  what  was  to 
come  next ;  no  expectation  would  be  aroused,  and 
consequently  there  could  be  no  mistakes. 

But  in  our  actual  world,  a  mixture  as  it  is  of  order  in  this  world 
and  anomaly,  illusions  seem  unavoidable.  If  we  ^^d^J^ect^ti™ 
could  confine  our  mental  life  to  bare  sensations  and  errors. 


io8  Experimental  Psychology 

their  sensory  associations  (as  some  have  erroneously 
beHeved  we  always  do),  if  we  could  stop  taking  our 
sensations  as  indications  of  something  more  impor- 
tant behind  them,  there  never  would  be  any  appear- 
ance contrary  to  reality.  The  oyster,  the  jellyfish, 
are  probably  under  few  illusions.  But  since  we  have 
developed  to  that  condition  where  we  are  no  longer 
satisfied  with  our  surface  impressions,  but  must  always 
be  asking  what  they  mean^  our  hope  lies  not  in  less, 
but  in  more  and  better  interpretations  of  them,  in 
discerning  truth  and  falsehood,  in  detecting  illusions 
when  they  come. 

How  are  And  SO  we  must  now  consider  the  problem  of  dis- 

disLgu^rhed  tinguishing  illusions  from  true  perceptions.     What  is 
from  true        the  psychological  difference  between  them,  and  how 
perceptions  ?  ^^^  ^^  detect  an  illusion  when  it  arises  .?     I   have 
already  pointed  out  the  similarity  of  illusions  and  per- 
ceptions.    In  no  case  do  we  have  an  immediate,  face- 
to-face  acquaintance  with  the  world ;  on  the  contrary, 
we  must  interpret  and  arrange  as  best  we  can   the 
mass  of  impressions  which  constantly  arise.     We  in- 
evitably form  some  judgment  of  what  they  signify. 
So  far  the  processes  of  illusion  and  of  perception  are 
alike ;  they  are  both  estimates  of  what  the  sensations 
stand  for. 
Is  the  differ-        What  is  the  difference  between  them  ?     One  feels 
fogTc^i  one^?"  tempted  to  say,  with  Sully,  that  the  difference  may 
be  described  as  a  logical  one  —  perception  being  a 
kind  of  correct  reasoning  from  the  data  or  premisses, 
while  illusions  are  fallacious  inferences.^     Much  can 

^  See  Sully,  Illusions :  A  Psychological  Study,  4th  ed.,  p.  335. 


Illusions  and  their  Significance  109 

be  said  in  favor  of  such  a  view.  There  is  a  remark- 
able similarity  between  perceiving  a  thing  correctly 
and  drawing  a  valid  conclusion  from  given  premisses. 
Our  perception  of  a  man,  for  example,  might  be  cast 
into  the  following  syllogistic  form  :  — 

Major  Premiss :  All  sensations  having  such  and  such 
definite  characteristics  are  signs  that  a  man  is  before  me. 

Minor  Premiss  :  Here  is  a  group  of  sensations  answering 
this  description. 

Conclusion:  Therefore  they  indicate  the  presence  of  a 
man. 

This  is  in  faultless  logical  form,  and  we  might  say 
corresponds  to  a  true  perception. 

But  one  becomes  less  confident  that  he  can  find  in  strictly,  both 
the  logical  character  of  the  act  the  difference  between  ^nd  mSn 
true  and  false  perception  when  he  tries  to  cast   an  are  fallacies, 
illusion  also  into  syllogistic  form.      Suppose  one  of 
us  to  be  laboring  under  an  hallucination  that  a  man 
is  before  us  when  in  reality  none  is  there.     Expanded, 
the  mental  process  might  be  stated  thus  :  — 

Major  Premiss :  All  sensations  having  such  and  such 
definite  characteristics  are  signs  that  a  man  is  before  me. 

Minor  Premiss :  Here  is  a  group  of  sensations  answering 
this  description. 

Conclusion :  Therefore  they  indicate  the  presence  of  a 
man  — 

the  very  statement  which  served  to  represent  the 
correct  perception.  The  mental  process  is  as  logi- 
cally consistent  in  the  one  case  as  in  the  other ;  con- 
sequently, so  far  as  valid  form  is  concerned,  illusion 
and  perception  are  absolutely  indistinguishable. 


no  Experimental  Psychology 

The  truth  is,  of  course,  that  while  the  conclusion  here 
in  both  cases  is  correctly  drawn  from  the  premisses, 
the  major  premiss  is  by  no  means  universally  true. 
We  are  not  justified  in  asserting  that  the  certain  defi- 
nite characteristics  referred  to  in  our  major  premiss 
are  the  infallible  sign  that  a  man  is  present,  since 
experience  actually  gives  instances  where  this  is  not 
the  case.  The  major  premiss  is  false  in  both  syllo- 
gisms, so  that  we  have  what  the  logicians  call  a  mate- 
rial fallacy  in  every  case  of  perception  as  well  as  of 
illusion.  Or  if  we  escape  the  material  fallacy  by  re- 
arranging our  premisses  to  read  :  — 

Major:  Every  real  man  gives  me  an  impression  of  a 
certain  definite  character. 

Minor :  Here  is  something  which  gives  me  such  an  im- 
pression. 

Conclusion :  It  must  be  a  man  — 

then  the  premisses  are  sound  enough,  but  we  have 
the  fallacy  of  "undistributed  middle,"  recognizable 
immediately  when  we  say,  — 

All  gold  glitters. 
This  thing  glitters. 
Therefore,  it  is  gold. 

andareindis-  And  since  the  correct  perception  takes  this  fallacious 
bylogic^^^*    form  quite  as  readily  as  does  the  illusion,  we  are  not 
aided  in  the  least  toward  an  accurate  statement  of  the 
^      difference  between  the  two. 

But  a  flaw  in  the  reasons  we  give  for  a  proposition 
of  course  determines  nothing  as  to  its  truth  or  falsity. 
We  give  bad  reasons  for  many  truths.  In  building 
up  our  experience  from  sense-impressions,  then,  we 


Illusions  and  their  Significance  iii 

fly  in  the  face  of  formal  logic.  We  jump  at  the  truth 
from  insufficient  evidence.  In  other  words,  we  take 
our  chances,  having  found  out  by  practical  life  that 
the  risk  of  error  is  relatively  small. 

But  if  logic  cannot  help  us  to  distinguish  true 
experience  from  deception,  since  both  are  condemned 
by  the  rigid  canons  of  deduction,  how  can  we  dis- 
tinguish them } 

A   ready  answer  would   be   that   our   perceptions  Can  illusions 
accord  with   the   facts,  while   our  illusions   do   not.  b^^^^og- 

nized  by 

According  to  this  view,  the  processes  themselves  going  direct- 
are  not  different ;  we  could  never  by  an  inner  analy-?  ^^  *°  ^^^^'^^  ** 
sis  of  the  mental  act  determine  whether  it  was  an 
illusion  any  more  than  we  could  take  a  photograph 
of  an  unknown  person  and  decide  by  chemical  analy- 
sis whether  it  was  a  good  likeness  or  not.  We  must 
go  outside  the  mental  process  and  compare  it  with 
external  reality;  then,  and  then  only,  have  we  any 
assurance  as  to  its  truth. 

This  test  of   illusion   is   intellectually  satisfactory  This  would 
only  up  to  a  certain  point.     For  on  closer  examina-  ge?outside*° 
tion  we  find  that  it  is  a  test  which  none  of  us  can  our  minds. 
use ;  it  is,  as  the  Arabs  say,  a  gift  of  almonds  to  the 
toothless.     The  outer  reality  would  be  a  serviceable 
criterion  of  illusion  if  we  could  be  at  once  within  our 
minds  and  outside  them,  so  as  to  compare  our  own 
mental  pictures  with   the   facts   as   they  really  are. 
But  we  cannot  escape  our  own  mental  bounds.     The 
idea  we  make  of  the  external  world  is  not  obtained  by 
some  immediate  and  unerring  intuition  ;  it  is  a  labori- 
ous construction  of  ours  out  of  our  individual  sense- 


112 


Experimental  Psychology- 


perceptions.  To  get  at  the  reality  by  which  we  are 
to  determine  the  accuracy  of  our  perceptions,  we 
have  to  depend  upon  the  very  images  and  processes 
whose  veracity  is  open  to  question.  Out  of  our  sen- 
sory images  —  a  mixture  of  perceptions  and  illusions 
—  we  have  to  decide  as  best  we  can  what  the  real 
world  is.  It  would  seem,  then,  that  instead  of  being 
able  to  test  illusions  by  our  knowledge  of  reality,  we 
must  first  be  able  to  sift  out  the  illusions  themselves 
from  our  truthful  perceptions  before  we  can  say  with 
decision  what  the  real  world  is. 


Experience  is 
used  to  check 


For  one  who  would  be  satisfied  with  no  test  which 
is  not  at  once  convenient  and  infallible,  the  case  must 
be  pronounced  hopeless.  Experience  in  this  regard 
always  reveals  a  curious  instance  of  working  in  a 
circle  :  we  cannot  be  certain  what  the  real  world  is 
without  distinguishing  illusions  from  perceptions ;  we 
cannot  distinguish  illusions  from  perceptions  without 
first  determining  what  the  real  world  is.  Here  is  a 
pretty  tangle  that  would  have  rejoiced  an  ancient 
sophist.  In  practical  life,  however,  we  never  stop 
to  untie  the  knot;  we  cut  it.  We  simply  put  our 
trust  in  the  general  run  of  experiences,  and  with  them 
as  standard  we  decide  the  worth  of  any  particular 
case.  Our  practical  test,  consequently,  is  whether 
the  special  interpretation  we  have  given  our  sensory 
impressions  accords  with  the  general  system  of  our 
experience.  If  past  experience  is  not  sufficient  to 
decide  the  case,  I  may  immediately  get  additional 
experience  to  see  whether  it  supports  or  condemns 
the  interpretation  I  have  made.     If  the  tactile  im- 


Illusions  and  their  Significance  113 

pressions  at  my  finger  tips  of  the  one  hand  sug- 
gest that  two  pencils  are  touching  me,  and  yet  the 
pencil  as  I  grasp  it  with  my  other  hand  gives  the 
clear  impression  of  but  a  single  object,  I  lose  faith 
in  the  first  interpretation  ;  and  if  sight,  moreover, 
assures  me  that  but  a  single  pencil  is  there,  I  re- 
ject the  early  impression  as  illusory.  But  if,  when 
any  of  us  put  a  single  pencil  between  our  crossed 
fingers,  the  double  tactual  impression  were  confirmed 
by  the  great  body  of  our  experience  —  if  we  not  only 
felt  two  pencils  between  the  two  crossed  fingers,  but 
also  felt  two  with  our  other  hand,  receiving  besides 
a  visual  impression  of  them  both,  and  had  hence- 
forth all  the  quiet  satisfaction  that  comes  from  pos- 
sessing two,  being  able  to  use  up,  lend,  or  mislay 
one,  and  still  have  the  other ;  and  if,  moreover,  our 
present  experience  accorded  with  our  memories  of 
past  experiences,  and  was  confirmed  by  the  testimony 
and  behavior  of  other  persons,  then  we  should  all 
regard  this  as  a  valid  perception  and  no  illusion  at  illusions  are 
all.  Our  only  way  of  recognizing  an  illusion  is  hy ,  J^j^^'J^^JP^^ 
the  fact  that  sooner  or  later  it  breaks  with  the  body  erai  system 


of  our  perceptions ;  one  of  our  other  senses,  or  the  ^^^^^^ 


of  expe- 

same  sense  under  different  conditions,  does  not  con- 
firm it,  or  it  is  confirmed  by  all  the  senses  for  a  while 
only.  Dreams  are  illusions  of  an  elaborate  kind,  and 
hold  together  marvellously.  So  long  as  all  the  parts 
do  hold  together,  there  is  no  knowing  whether  we 
are  dreaming  or  awake.  But  after  a  while  the  bubble 
bursts ;  tlie  dream  forms  disappear  as  things  in  real 
life  never  do,  an  influx  of  law-abiding  experiences 
occurs,  fitting  into  the  still  larger  system  of  memo- 


insane. 


114  Experimental  Psychology 

ries  and  associations,  and  in  comparison  with  these 
the  dream  group  immediately  seems  fantastic  and 
unreal. 

It  is  clear,  therefore,  that  we  do  not  go  outside  our 
minds  to  detect  illusions ;  we  have  no  immediate  view 
of  reality  by  which  we  may  decide  their  truth.  The 
experiences  themselves  are  employed  to  judge  one 
another.  For  most  of  us  there  is  a  stable  mass  of 
perceptions  which  offers  a  good  practical  criterion  in 
This  test  any  questionable  case.  But  there  are  unfortunates 
fails  in  the  whosc  experience  does  not  allow  so  ready  a  dis- 
crimination.  In  the  insane,  the  figures  of  imagina- 
tion form  such  abiding  and  consistent  groups,  they 
occur  in  such  orderly  array,  that,  in  time,  the  usual 
tests  of  reality  fail.  Their  hallucinations  show  so 
many  of  the  marks  of  reality,  that  the  patient  is 
finally  at  a  loss  to  tell  what  is  real  and  what  is  not. 
Or  if  he  still  have  power  to  make  this  distinction,  the 
effort  of  attention  which  this  requires  becomes  too 
great,  he  gives  up  the  struggle,  and  finally  allows 
fact  and  fancy  to  mingle  in  wild  confusion. 

The  relation  of  any  given  item  to  our  whole  ex- 
perience, consequently,  determines  whether  it  is  real. 
It  is  not  sufficient  that  the  experience  have  a  basis  in 
sensation,  as  is  sometimes  said.  Our  illusions  usu- 
ally have  in  them  sensations  enough ;  what  they 
lack  is  harmony  with  the  whole.  They  are  discord- 
ant elements  that  refuse  to  clasp  hands  with  the  rest 
of  our  world,  and  so  are  adjudged  unreal.^ 

And  yet,  in  strictness,  even  our  illusions  are  not 

1  As  regards  the  view  that  the  supreme  test  of  reality  is  a  social  one, 
cf.  p.  157. 


Illusions  and  their  Significance  115 

unreal.  Our  dreams  are  real  dreams  ;  hallucinations  Seen  aright, 
are  real  hallucinations.  So  that,  even  in  these  cases,  hirmonize  "^ 
we  are  face  to  face  with  a  fact  of  the  world  and  not  with  the  sys- 
with  a  nonentity.  And  for  this  reason,  even  our  de-  *^°^* 
ceptions  must  in  some  way  belong  to  that  harmonious 
system  of  experience  which  I  have  tried  to  show  is 
our  final  test  of  what  is  real.  We  may  speak  as  if 
they  were  rejected  because  they  would  not  accord 
with  the  system.  This,  however,  we  may  now  see  is 
only  a  convenient  half  truth.  If  our  illusions  were 
not  somehow  in  harmony  with  the  whole,  our  scien- 
tific faith  leads  us  to  believe  that  they  would  never 
occur.  The  discord  arises  because  we  try  to  put 
them  in  the  wrong  part  of  the  system.  They  have  a 
proper  place ;  they  belong  among  our  personal  and 
mental  acts,  and  not  in  the  physical  world ;  and 
rightly  understood  they  harmonize  beautifully  with 
the  general  character  of  experience.  For  the  psy- 
chologist, they  fit  perfectly  into  the  mental  system ; 
they  are  among  its  interesting  realities.  He  scruti- 
nizes them,  he  measures  and  times  them,  and  many 
he  can  explain.  Pure  unrealities,  of  course,  could  not 
be  dealt  with  thus. 

A  healthy  mind  will,  consequently,  find  in  illusion  They  do  not 
no  ground  for  discouragement.     From  time  immemo-  jrustofthe 
rial,  the  errors  of  sense  have  been  pointed  to  as  a  mind. 
proof  of  the  unreliabiHty  of  our  powers.     How  can 
we  be  sure  of  anything,  when  our  simplest  faculties, 
our  processes  which  come  closest  to  external  reality, 
are  so  deceptive .?     But  this  is  only  one  side  of  the 
case.     There  is  also  the  other  side,  that  we  not  only 
have  illusions,  but  we  know  that  we  have  them ;  and 


ii6  Experimental  Psychology 

the  power  of  detecting  them  ought  to  give  us  quite 
as  much  ground  for  congratulation  and  self-confidence 
as  the  illusions  themselves  do  for  distrust.  If  it  were 
not  for  the  general  soundness  of  our  life,  we  should 
never  be  aware  that  anything  was  amiss.  So  that  no 
doctrine  of  total  intellectual  depravity  can  ever  be 
supported  by  appeal  to  the  deceptions  of  sense. 
They  are  rather  an  evidence  that  in  the  perceptual 
life,  as  elsewhere,  there  is  a  mingUng  of  good  and 
evil,  of  true  and  false.  And  since  experience  shows 
that  along  with  the  errors  comes  also  the  power  of 
correction,  knowledge  is  in  the  ascendant,  and  the 
future  is  secure. 

Shall  we  conclude,  then,  that  a  more  perfect  men- 
tal adjustment  will  free  us  from  illusions  ?  It  might 
seem  from  what  was  said  earlier  that  such  would 
be  the  case.  If  illusions  spring  from  misinterpre- 
tation,—  spring  not  from  our  sensations,  but  from 
the  way  we  mentally  supplement  our  sensations,  —  it 
would  seem  that  when  once  we  knew  the  truth  the 
illusions  would  be  dispelled.  As  a  fact,  however, 
many  illusions  will  not  down  even  when  we  know 

Fig.  21, — Munsterberg's  figure  (slightly  modified). 


their  character.  Even  after  we  know,  for  instance, 
that  the  contiguous  edges  of  the  squares  in  Miinster- 
berg's  figure  (Fig.  21)  run  parallel  to  the  lines  ad  and 
cd,  the  appearance  remains  contrary  to  this  knowl- 
edge.    And  we  may  measure  with  compasses  and 


Illusions  and  their  Significance  117 

convince  ourselves  that  the  lower  of  the  concentric 
arcs  above  the  horizontals  in  Fig.  22  is  the  contin- 
uation of  the  curve  below  the  lines,  and  yet  the 
upper  persistently  appears  to  have  this  character; 
and  so  with  a  host  of  other  illusions.     The  fact  that 


4-0 

Fig.  22.  —  The  lower  of  the  arcs  above  the  horizontal  is  the  continuation 
of  the  curves  a  and  b.     (Verified  by  measuring  from  the  centre  c.) 

further  knowledge  does  not  destroy  their  sensible 
force  demonstrates  how  complicated  the  mind  is, 
and  what  inconsistencies  it  can  harbor.  Our  modes 
of  interconnecting  and  interpreting  our  sensations 
are  due  to  deep-seated  mental  habits,  lying  beyond 
the  immediate  control  of  our  will,  and  even  to  a  large 
extent  beyond  the  influence  of  logical  evidence. 
They  have  become  ingrained  through  the  hard 
schooHng  of  years  and,  possibly,  of  generations. 
The  judgment  from  the  evidence,  however,  —  our 
knowledge  of  what  the  unperceived  facts  behind 
the  illusions  are,  —  lies  on  the  surface,  and  does 
not  penetrate  into  the  deeper  mental  constitution. 
Illusion  is  consequently  compatible  with  perfect  illusion  is 
knowledge ;  and  a  higher  mental  plane  would  assure  ^^th^^gj-fect 
us  only  of  the  power  to  see  through  all  deceptions,  knowledge, 


Ii8  Experimental  Psychology 

but  would  be  no  guarantee  that  the  illusions  them- 
selves would  disappear.  They  would  simply  lose 
their  power  to  mislead  us ;  they  would  not  be  delu- 
sions^ nor  would  they  in  any  wise  obscure  our  practi- 
cal and  moral  relations.  As  soon  as  we  are  able  to 
see  around  or  through  an  illusion,  it  is  no  longer  a 
hindrance,  no  longer  a  handicap,  and  consequently 
the  process  of  natural  selection  or  of  adaptation  to 
the  environment  cannot  be  depended  upon  to  eradi- 
cate it.  In  fact,  we  may  go  farther  than  to  say  that 
illusions  will  continue  because  there  is  no  especial 
need  of  our  ridding  ourselves  of  them,  or  that  they 
will  remain  by  inertia,  for  want  of  an  opposing 
force.  There  is  a  positive  utility  of  a  higher  kind 
in  certain  illusions.  Judged  by  the  standards  of 
biology,  they  are  defects;  they  are  signs  of  an  im- 
perfect adaptation  of  the  mind  to  its  environment. 
But  this  is  only  half  the  truth.  They  are  deficiencies 
that  leave  us  the  richer.  For,  having  discovered  that 
they  exist,  mankind  makes  them  of  service  in  that 
half-practical  world  of  play  and  art.  How  much  of 
the  fascination  of  picture  and  of  drama  depends  upon 
the  Hght  veil  of  illusion  that  floats  over  the  whole, 
so  fine  that  we  at  once  see  it  and  see  through  it. 
We  have  here  the  curious  pleasure  of  being  deceived 
and  yet  a  party  to  the  fraud.  If  the  deception  were 
perfect,  it  would  be  mere  trickery;  and  yet,  too,  if 
there  were  no  deception,  we  should  lose  some  subtle 
charm.  If  illusions,  then,  are  to  be  described  in  pro- 
saic scientific  terms  as  cases  of  defective  adaptation, 
may  the  defect  in  some  faint  form  continue  in  this 
life  and  in  the  world  to  come ! 


Illusions  and  their  Significance  119 

In  concluding,  let  us  recall  the  main  teaching  of  The  main 
illusions   in   regard   to   the   character  of   the   mind.  If^^l^^^g^^ 

°     ,  illusions. 

They  show  the  interplay  of  the  different  sides  of 
consciousness.  Attention  influences  judgment,  and 
expectation  affects  sensation.  There  are  no  sharp 
borders  here.  The  usual  divisions  we  make  in  psy- 
chology are  not  divisions  in  the  facts  themselves; 
there  are  no  functions  which  act  in  isolation  and 
without  mutual  dependence.  Illusions,  then,  bring 
home  to  us  the  organic  unity  of  the  mind;  they  make  Mentally,  aii 
it  evident  that  the  various  sides  are  in  constant  sym-  *^'."^^  ^°"" 

'J  spire. 

pathy  and  interaction,  and  that  to  some  extent  eachi 
participates  in  all  that  is  done. 

But  the  more  specific  teaching  is  as  to  the  manner  Refutation 
in  which  experience  is  constructed.  Illusions,  when  'f^^^^^J'^ 
understood,  are  the  most  striking  refutation  of  the  trine, 
common  belief  that  experience  is  a  kind  of  direct  im- 
press of  external  nature,  we  being  passive  recipients 
of  the  facts  as  the  world  imprints  them  upon  our 
senses.  There  is  a  passage  in  the  Thecstetus  which 
sounds  odd  enough  to  our  modern  ears,  but  which 
seems  to  be  a  foreshadowing  of  the  truth.  From  the 
outer  object,  Plato  tells  us,^  there  comes  an  image 
toward  the  eye  ;  and  out  from  the  eye  there  flows 
sight  to  meet  the  object.  The  union  of  these  two 
somehow  produces  our  actual  perception  of  the  thing. 
Curious  as  we  may  account  this  early  psychology,  it 
expresses  the  truth  that  experience  arises  by  a  union 
of  two  different  factors  —  something  which  comes 
from  the  outer  world,  and  something  which  we  our- 
selves contribute  from  our  inner  store.     The  outer 

1  Thecetetus,  Staph.,  156. 


I20  Experimental  Psychology- 

impression  alone,  according  to  Plato,  is  not  enough ; 
we  must  do  our  part ;  we  must  meet  the  impressions 
halfway.     The  outgoing  sight  darting  from  the  eye 
to  meet  the  image  coming  from  the  object,  seems  to 
represent  what  we  now  call  our  subjective  elaboration 
of  the  incoming  impressions  —  represents  the  associa- 
tions or  suggestions  which  these  impressions  arouse, 
— the  form  or  arrangement  into  which  we  force  them, 
and  without  which  the  bare  sensations  would  have  no 
meaning  whatever. 
Experience         So  long  as  our  Contribution  to   the  experience  — 
cTs^ant ai'tiv-  ^^^  associatious,  the  suggestions,  the  "form"  —  is  in 
ity  on  our       perfect  keeping  with  the  outer  facts,  we  might  well 
^^^^'  believe  that  external  nature  itself  was  the  sole  and 

efficient  cause  of  our  panorama  of  the  world,  that 
we  had  really  received  the  experience  bodily  from 
the  objects  themselves.  But  the  frequency  of  decep- 
tive experiences,  of  perceptions  contrary  to  fact,  makes 
us  see  that  this  cannot  be ;  that  we  ourselves  are  all 
the  while  a  chief  source  of  experience.  Deprived  of 
,  the  outer  world,  we  should  indeed  be  without  the  crude 
j  materials  of  experience ;  but  the  finished  product,  the 
'  real  vision  of  nature  and  of  history,  depends  quite  as 
much  upon  us.  The  world,  then,  is  beheld  by  us  only 
indirectly,  as  we  reconstruct  it  out  of  our  sensations. 
Like  the  Lady  of  Shalott,  each  of  us  views  the  gay 
pageant  of  Ufe  as  in  a  glass,  and  even  this  reflected 
image  comes  to  us  only  as  we  keep  to  our  task.  Once 
we  cease  our  activity,  once  we  stop  our  weaving,  at 
that  instant  —  as  in  the  poem  —  the  glass  breaks,  the 
vision  vanishes,  and  around  us  Hes  but  the  tangled 
web  of  meaningless  impressions.     The  chief  psycho- 


Illusions  and  their  Significance  I2i 

logical  significance  of  illusions,  then,  is  to  bring  out 
the  fact  that  the  mind,  even  in  what  appears  its  most 
passive  moments,  is  in  ceaseless  activity,  and  that 
its  various  powers  of  intellect  and  feeling  and  will 
constantly  interplay.  These  illusions  thus  force  us 
to  the  paradox  that  our  very  deceptions  are  an  im- 
portant instrument  of  knowledge. 


CHAPTER  VII 

EXPERIMENTS  ON  MENTAL  SPACE,  PARTICULARLY 
THE   SPACE   OF   THE   BLIND 


Kant  and  the 
psychology 
of  space. 


\. 


Interest 
aroused  by 
modern 
geometry. 


The  various  questions  connected  with  our  percep- 
tion of  space  were  given  by  Kant  a  dignity  that  they 
had  not  before  possessed.  Locke  and  Berkeley  had 
already  made  the  subject  inviting,  but  Kant  brought 
it  to  the  front  as  one  of  the  crucial  problems  in  re- 
gard to  mind.  Our  view  on  this  subject,  he  showed, 
would  to  a  large  extent  indicate  what  our  belief  as  to 
the  validity  and  range  of  human  knowledge  in  gen- 
eral should  be.  Under  the  influence  of  Kant's  doc- 
trine that  our  perception  of  space  is  somehow  on  a 
different  mental  level  from  our  perception  of  light  or 
of  sound,  and  that  it  indicates  the  possession  of  mental 
powers  transcending  the  impressions  of  the  moment, 
the  psychology  of  space  became  a  thing  of  flesh  and 
blood,  and  has  ever  since  remained  so.  Against  Kant 
are  the  British  ranks  from  Hume  to  Spencer,  main- 
taining that  there  is  nothing  anomalous  here,  noth- 
ing that  points  to  peculiar  or  transcendent  powers ;  it 
is  all  a  matter  of  sensations  and  their  association. 

The  interest  which  the  psychology  of  space  has 
derived  from  these  contentions  has  been  recently 
stimulated  from  an  unexpected  quarter.  The  dis- 
pute as  to  the  character  of  our  space-experience  has 
broken  out  in  mathematics.     Many  now  believe  that 


Experiments  on  Mental  Space  123 

what  had  been  so  long  accepted  as  demonstrable 
in  regard  to  space  —  for  example,  that  the  interior 
angles  of  a  plane  triangle  are  equal  to  two  right 
angles  —  is,  after  all,  but  characteristic  of  the  partic- 
ular space  with  which  we  are  familiar,  and  that  there 
is  at  least  the  possibility  of  other  kinds  of  space 
whose  properties  would  not  accord  with  the  principles 
of  the  older  mathematics.  Out  of  such  speculations 
has  developed  the  modern  non-Euclidean  geometry. 

The  work  of  the  laboratory,  and  of  the  experi- 
menters outside  the  laboratory,  —  of  the  surgeons, 
for  instance,  who  have  contributed  so  much  to  our 
knowledge  here,  —  is  in  sight  of  these  interesting 
questions ;  but  they  must  remain  in  the  background 
until  the  details  of  the  experimental  studies  have 
been  brought  more  clearly  before  us. 

We  all  have  an  instinctive  feeling  that  our  mind  The  marvel 
reaches  out  into  our  very  skin,  and  is  in  the  actual  °^  *^  ^^^^  ^ 
presence  of  the  objects  that  touch  us.      Sight  also 
seems  to  bring  us  face  to  face  with  the  world,  as  if 
we  looked  out  at  it   directly  through   the  pupil  of 
the  eye.     But  the  more  prosaic,  and  yet,  after  all, 
more  wonderful  fact  is  that  the  mind  receives  only  . 
indirect  reports  of  what  is  going  on  without.     The  ^ 
cortex  of   the  brain,  with  which  our  consciousness 
is  connected,  lies  in  darkness,  deep  in  its  coatings  of 
tough  membrane  and  skull  and  flesh,  and  connected 
with  the  outer  world  only  through  the  medium  of 
long  and  delicate  fibres  that  bring  in  messages  from  \ 
the  outposts  of   sense.     It  is  as  if   a  person  were 
secluded  in  an  inner  chamber  and  learned  of  the  out- 


124 


Experimental  Psychology 


The  limit  of 
its  power 


side  world  only  by  an  inconceivably  elaborate  system 
of  wires  and  signals.  From  some  difference  in  the 
signals  accompanying  the  different  messages,  or  from 
some  peculiarity  either  of  the  tone  or  of  the  intercon- 
nection of  the  messages  themselves,  we  are  able  to  pic- 
ture the  scene  which  is  causing  the  influx  of  sensations. 
The  mind  must  distinguish  the  various  impressions 
from  different  parts  of  the  skin,  or  from  the  innumer- 
able points  on  the  surface  of  the  eye,  and  refer  each 
to  its  proper  place  in  the  external  world.  When  one 
considers  the  complexity  of  the  task,  —  that  we  can 
accurately  tell  not  only  the  direction  but  also  the 
ever  changing^  distance  from  which  sensations  come 
through  the  rods  and  cones  of  the  ey es^  —  the  ease 
and  security  with  which  this  amazing  performance  is 
accomplished  is  one  of  the  marvels  of  life. 

Experiment  shows,  however,  that  there  is  a  limit 
even  to  this  power.  When  impressions  come  from 
points  too  close  together  we  are  at  last  unable  to 
keep  them  apart.  In  the  case  of  sight  this  limit  is 
very  low :  fine  lines,  side  by  side,  become  con- 
fused and  indistinguishable  when  the  distance 
between  them  makes  an  angle  in  vision  of  less 
than  about  60" .  Stars  in  the  heavens  cannot 
be  seen  as  separate  when  they  are  closer 
together  than  3o'^  Under  more  favorable 
conditions,  however,  we  can  distinguish  posi- 
tions that  are  as  close  together  as  7^'  of  arc, 
or  about  -^^  of  a  degree.  When,  for  instance, 
two  lines  are  placed  end  to  end,  and  one  of  them  is 
shifted  slightly  to  one  side,  as  in  the  diagram  (Fig.  23), 
while  still  remaining  parallel  with  the  other,  a  dis- 


FiG.  23. 


Experiments  on  Mental  Space  125 

placement  of  J  of  an  inch  can  be  detected  at  a  dis- 
tance of  about  400  feet.^  This  means  that  in  the 
minute  image  at  the  back  of  the  eye,  differences  of 
locality  amounting  to  but  -5-0^-00"  ^^  ^^  i"^^  ^^i^^  ^ive 
distinguishable  impressions !  Touch,  while  not  so 
delicate  as  this,  is  also  capable  of  exceedingly  fine 
perceptions.  An  elevation  of  but  g-^Vo  of  ^^  ii^ch 
above  a  smooth  surface  is  noticed  by  rubbing  the 
finger  tips  over  it.^  But  in  experiments  where  we 
have  to  tell  whether  we  are  being  touched  by  one  or 
by  two  points,  even  at  the  finger  tips  we  can  scarcely 
distinguish  impressions  that  are  2V  ^^  ^^  i^^l^  apart ; 
and  on  our  backs  we  often  confuse  sensations  that 
are  separated  as  much  as  two  inches. 

Our  first  thought  might  be  that  the  limit  in  all  seems  not  to 
these  cases  is  fixed  by  anatomical  conditions;  that  Jf  ^^^^^y 

J  '  the  sense- 

the  different  impressions  when  they  come  too  close  organs, 
together  run  on  to  the  same  sensory  terminals,  and 
tl;us  become  confused.  But  the  minimum  is  more 
variable  and  often  much  smaller  than  it  would  be  if 
due  to  a  limit  in  the  supply  of  nerve  endings.  In  the 
case  of  touch,  a  few  days'  practice  in  feeling  compass- 
points  will  reduce  the  threshold  to  a  small  fraction  of 
what  it  was ;  and  reduce  it  not  alone  at  the  part  of 
the  skin  where  the  practice  has  been  given,  but  at 
other  parts  as  well.      We  can  hardly  believe  that  the 

1  Cf.  "A  New  Determination  of  the  Minimum  Visibile,"  etc.,  in 
the  Psychological  Review  for  September,  1900  (Vol.  VII,  p.  429),  and 
also  in  the  Compte  Rendu  des  Seances^  IV^  Congres  International  de 
Psychologies  Paris,  1901,  p.  411.  Cf.  .Bourdon,  "  L'acuite  stereo- 
scopique,"  Revue  Philosophique,  January,  1900. 

2  Brown,  "  Notes  on  a  New  Form  of  ^sthesiometer,"  Journal  of 
Physiology,  Vol.  27,  p.  85. 


126 


Experimental  Psychology 


How  this  is 
possible. 


Simile  of  a 

signal 

system. 


supply  of  nerves  is  correspondingly  altered  at  such 
short  notice.  And  in  vision  our  discrimination  seems 
about  four  times  as  fine  as  it  ought  to  be,  if  the  merely 
anatomical  measurements  of  the  rods  and  cones  in  the 
eye  determined  its  limit.^ 

Any  full  explanation  of  this  curious  phenomenon 
would  take  one  far  into  technicalities ;  but  perhaps 
some  assistance  in  clearing  up  the  paradox  that  local- 
ization is  finer  than  nerve  differences  may  be  had 
from  keeping  in  mind  that  even  the  finest  impressions 
never  come  from  a  single  isolated  nerve  terminal  in 
the  eye,  and  probably  do  not  in  the  skin.  This  is 
shown  in  vision  by  the  well-known  phenomena  of 
irradiation  and  of  contrast,  which  prove  that  even  the 
smallest  ray  of  light  stimulates  not  alone  the  part  of 
the  eye  on  which  it  directly  falls,  but  also  the  neigh- 
boring regions,  as  by  some  subtle  sympathy  between 
the  different  parts  of  the  retina.  The  nervous  ele- 
ments thus  respond  always  in  groups  and  never  sin- 
gly. So  that  the  space-signal  by  which  the  place  of 
origin  of  a  sensation  is  designated  is  not  some  simple 
sign  comparable  to  the  single  numeral  which  drops 
down  in  our  electric  signal  boxes  when  the  bell  rings, 
but  must  be  a  number  of  simultaneous  signals,  where 
'the  pecuHar  grouping  tells  much  more  than  any  one 
of  them  could  tell  alone.  Imagine  an  electric  signal- 
box  where  the  room  in  the  house  from  which  each 
signal  came  was  denoted  not  by  a  single  falling  nu- 
meral, but  by  the  simultaneous  flashing  of  a  great 
number  of  lights  in  the  box,  and  this  was  moreover  so 
delicately  constructed  that  each  light  passed  through 


1  See  the  "  New  Determination,"  etc.,  cited  just  before. 


Experiments  on  Mental  Space  127 

various  gradations  of  intensity,  or  changed  its  color 
according  as  the  person  giving  the  signal  was  nearer 
or  farther  from  the  button  that  controlled  the  signal. 
In  that  case  any  one  would  have  sufficient  data  to 
know  not  only  the  room  from  which  the  signal  issued, 
but  could,  according  to  his  training  and  mother-wit, 
determine  up  to  any  degree  of  exactness  the  particu- 
lar spot  in  the  room  where  the  person  who  gave  the 
signal  stood.  The  limit  of  the  number  of  wires  in 
the  house  and  the  distance  apart  of  their  terminals 
would  in  this  case  not  limit  the  exactness  of  the 
localization  of  the  summons.  The  local  signs  with  us  The  mental 
seem,  from  the  experimental  evidence,  to  be  of  this  ^ocaUty 
complicated  order  —  endless  changes  and  rearrange- 
ments in  the  impressions  coming  from  joints  and 
tendons  and  muscles  and  skin  and  retina.  The  con- 
scious discrimination  of  place,  therefore,  is  a  high 
order  of  mental  achievement  —  not  mere  rote-work 
nor  rule-of-thumb  action,  by  any  means.  No  two 
places,  however  close  together,  can  give  exactly  the 
same  combination  of  sensations ;  there  will  inevitably 
be  some  difference  in  their  relatiyejatensities  or  qjial-  ' 
ities.  But  there  is  a  limit  to  our  power  of  following 
these  infinite  gradations  and  combinations,  and  in 
this,  rather  than  in  the  distance  apart  of  the  nerve 
terminals  in  the  eye  or  in  the  skin,  must  we  look  for 
the  causes  that  determine  the  spatial  threshold. 

Thus   far   it  has   been   tacitly  assumed   that  our  which  is  the 
acquaintance  with  space  comes  through  both  touch  ^f^^^fj^^^^ 
and  sight  independently.     But  psychologists  are  di-  ceiuncef 
vided  into  parties  on  this  very  question.     First,  there 


128  Experimental   Psychology- 

are  the  tactualists,  as  we  might  call  them,  who  be- 
lieve that  touch  (including  our  muscular  impressions^ 
is  the  spatial  SQnst  par  excellence^  and  that  sight  alone 
cannot  acquaint  us  with  the  size  or  shape  or  distance 
or  direction  of  things.  On  the  other  hand,  there  are 
the  visualists,  who  maintain  that  sight  is  the  only 
sense  that  gives  us  a  knowledge  of  these  things; 
that  touch  is  a  mere  time-sense  and  gives  us  no  feel- 
ing of  space  whatever.  And  finally,  there  are  some 
who  hold  that  touch  and  sight  perform  this  work  in 
common ;  that  each  of  them  is  capable  of  space-per- 
ception, and  that  we  consequently  cannot  attribute 
this  to  either  of  the  senses  as  its  peculiar  and  exclu- 
sive function. 
The  parti-  The  question  is  an  old  one.     The  classic  query  of 

Molyneux  to  Locke  as  to  whether  a  man  born  blind 
who  had  become  familiar  with  a  cube  and  sphere  by 
touch  could,  if  suddenly  given  sight,  correctly  dis- 
tinguish and  name  each  of  these  by. vision  alone, 
shows  the  problem  in  its  early  form.  For  if  touch 
and  sight  had  space  as  their  common  feature,  we 
should  expect  that  a  person  who  had  become  ac- 
quainted with  a  form  by  one  of  these  senses  would 
immediately  recognize  it  when  this  same  form  ap- 
peared to  the  other  sense.  Locke  believed  that  such 
a  recognition  would  not  be  possible ;  and  Berkeley's 
"New Theory  of  Vision,"  going  much  more  thoroughly 
into  the  underlying  psychology  of  the  question,  ar- 
rives at  a  conclusion  ^  quite  in  agreement  with  Locke. 
Berkeley  was,  in  fact,  the  first  to  develop  systemati- 
cally the  notion  that  vision,  in  its  primitive  purity, 

iSeep.s. 


sans  of  touch. 


Experiments  on   Mental  Space  129 

lacks  all  space-character,  and  that  it  gets  this  only 
indirectly  by  association  with  tactile  impressions.  By 
long  association,  he  believed,  sight  comes  to  suggest 
tactual  experiences  which  are  spatial,  and  consequently 
comes  to  suggest  space,  although  the  visual  experi- 
ences themselves  are  spaceless ;  just  as  the  odor  of 
brass  might  suggest  weight  and  resistance  without 
the  olfactory  sensations  themselves  having  weight 
and  resistance. 

The  most  striking  evidence  on  this  question  comes  Experiments 
from  experiments  on  persons  born  blind,  and  given  after  opera- 
relief  comparatively  late  in  life  by  surgical  aid.     In  congenital 
a  number  of  such  cases,   after  the  patient   had  to  *^^^^'^^'^*- 
some  extent  recovered  from  the  operation,  he  was 
allowed  to  look  at  objects  already  familiar  by  feeling, 
and  was  asked  to  name  them.     From  CheseJden's  fa- 
mous case  down,  the  testimony  is  fairly  uniform  that 
the  patient  cannot  recognize  objects  by  sight  alone.' Usually, 
He  must  first  touch  the  thing  or  he  fails  to  identify  ^^"j"^^'  °^ 

o  •/     jects  are  un- 

it.   But  once  he  has  learned  how  the  felt  thing  looks,  recognized 

thereafter  the  sight  of  it  suffices  for  its  recognition,  ^y^'^^*- 
Cheselden's  patient,  on  seeing  a  familiar  cat,  could 
not  tell  what  it  was.  Home's  patient  thought  that 
a  number  of  square  and  oblong  cards  were  round ; 
while  Raehlmann's  patient,  when  shown  a  large  bottle, 
said  it  might  be  a  horse.  And  when  one  of  the  sur- 
geons twitted  him  on  not  knowing  the  difference  be- 
tween the  two,  he  replied  sheepishly  that  it  was  not 
so  easy  after  all.^    The  young  gentleman  operated  on 

1  For  the  more  detailed  references  and  a  discussion  of  these  cases 
and  of  those  cited  below,  cf.  "The  Spatial  Harmony  of  Touch  and 
Sight,"  Mind,  October,  1899. 
K 


ijo  Experimental  Psychology 

by  Franz,  however,  was  the  most  intelligent  and  best 
educated  of  them  all ;  and  he  was  able,  by  very  close 
attention,  to  distinguish  a  square,  a  circle,  and  a  tri- 
angle ;  but  he  afterward  confessed  that  the  character 
of  the  figures  did  not  become  clear  to  him  until  he 
seemed  to  feel  them  with  his  finger  tips.  Then,  al- 
though he  was  not  actually  touching  them,  he  recog- 
nized the  forms  immediately.  And  again,  in  pointing 
out  which  of  two  lines  was  horizontal  and  which  was 
vertical,  he  first  carried  his  finger -cautiously  to  the 
wrong  one,  and  then  corrected  himself.  Trinchinetti's 
little  boy  and  girl  grasped  at  things  as  if  they  ex- 
pected to  find  them  in  the  neighborhood  of  their  eyes. 
So,  too,  Dufour's  patient,  when  asked  to  take  hold  of 
a  door-knob  which  he  seemed  to  see,  groped  around 
for  it  like  one  in  the  dark.  Rarely  in  these  persons 
does  sight  seem  to  have  been,  at  first,  of  much  assist- 
ance in  guiding  their  movements ;  in  fact,  one  of  the 
patients,  even  weeks  after  the  operation,  could  hardly 
be  induced  to  take  a  practical  interest  in  what  his  eyes 
revealed.  He  would  neglect  the  reports  of  sight,  and 
fall  back  persistently  into  his  old  world  of  tactile  clews. 
The  results  Such  observations  are  made  much  of  as  evidence 
seem  to  favor  ^|^^^  sight  in  its  virgin  state  gives  us  no  idea  of  space 
ists'view.  whatever.  For,  if  the  things  of  sight  were  really 
spatial,  it  is  argued,  why  did  these  patients  find  the 
/  visual  world  such  an  unfamiliar  land  ?  Even  though 
the  sense-materials  were  entirely  novel,  the  old  forms, 
it  would  seem,  ought  to  be  recognizable  if  there  were 
actually  a  common  element  of  space  in  the  two  kinds 
of  experience.  Do  not  the  experiments,  therefore, 
show  that  Berkeley  was  right,  and  that  until  associa- 


Fig.  24.  —  A  negative  of  Fig.  25. 


Experiments  on  Mental  Space  131 

tions  have  had  time  to  develop,  touch  and  sight  have 
absolutely  nothing  in  common  ? 

It  does  not  seem  to  me  that  they  mean  this.     To  Possibility  of 
show  that  they  can  well  be  interpreted  in  another  way  f^fg^^/eta- 
will  require  a  somewhat  long  discussion ;  but  the  sub-  tion. 
ject  is  so  interesting  and  so  important  that  a  careful 
weighing  of  the  evidence  may  not  seem  out  of  place. 
The  evidence  against  there  being  any  underlying  simi- 
larity between  touch  and  sight  is,  as  has  been  seen, 
based  largely  upon  the  failure  to  recognize  by  sight 
objects  known  by  touch. 

But  in  the  first  place  it  must  be  remembered  that  a  Difficulties  of 
person  is  at  a  great  disadvantage  immediately  after  a  surgiJa^i  ^^^ 
surgical  operation  on  his  eyes.     There  are  often  pain  operation, 
and  tears,  and  at  best  the  eyes  are  not  well  under 
control.     A  lack  of  proper  accommodation  and  co-  \ 
operation  of  the  two  eyes  must  make  the  impressions 
which  they  give  far  from  clear.    But  if,  for  this  reason, 
one  sees  men  as  trees  walking,  his  experience  is  never- 
theless quite  as  spatial  as  if  he  sees  them  as  men.    The 
difficulty  may  be  largely  in  telling  where  one  thing 
leaves  off  and  another  begins ;  so  that  object  and  sur- 
roundings and  background  are  poorly  discriminated. 
Mere  vagueness  of  impression  is  doubtless  partly  the 
cause  of  the  defective  recognition.    But  vagueness  of 
objects  is  by  no  means  equivalent  to  absence  of  ex- 
tension.    In  gloom  or  mist  we  often  fail  to  identify 
things,  and  yet  they  are  certainly  spatial. 

But  even  disregarding  this,  the  fact  is  that  in  our  Recognition 
usual  recognition  of  things  we  depend  comparatively  ^^^cTbe-"^ 
little  on  their  pure  space-form.  Take  so  simple  an  sides  spatial 
instance  as  that  of  the  tin  cup  which  Johann  Ruben,    °^"^* 


132  Experimental  Psychology 

in  Raehlmann's  account,  could  not  tell  by  sight. 
Many  would  perhaps  say  that  we  appreciate  that 
such  an  object  is  a  cup  by  the  shape  of  the  thing, 
and  that  nothing  else  about  it  is  of  great  importance. 
But  imagine  yourself  searching  for  a  tin  cup  in  the 
dark  and  suddenly  laying  your  hand  on  something 
the  shape  of  a  cup  but  made  of  ice  or  butter;  the 
chances  are  that  none  of  us  would  take  it  for  a  cup 
at  all.  What  we  should  mark  would  be  the  damp, 
sHppery  feeling  of  the  thing,  and  these  would  be  so 
prominent  that  the  form  would  pass  unnoticed. 

Now  it  could  quite  as  well  be  urged  that  touch  here 
gave  us  no  sense  of  form  because  we  might  not  dis- 
cern the  shape  of  the  icy  or  buttery  thing,  as  that  the 
newly  attained  sight  gives  no  sense  of  shape  because 
mere  shape,    these  patients  fail  to  recognize  objects  by  their  shape. 
In  their  case  the  visual  sense-filling  of  the  object 
is  infinitely  novel  and  unexpected,  infinitely  removed 
from  the  familiar  temperature  and  hardness  and  re- 
sistance in  which  the  shapes  of  things  had  hitherto 
been   embodied.      The  color,  the  glitter,  the   shad- 
ows around  and  upon  each  object,  are  something  for 
^  which  touch  offers  no    counterpart  whatever.     And 
these  unexpected  properties  are  so  absorbing,  so  baf- 
fling, that  the  abstract  space-quality,  the  bare  geo- 
metric character  of  the  thing,  fails  to  come  to  the 
front.     The  other  aspects  crowd  forward  and  leave 
no  interest  for  these  more  hidden  marks. 
Recognition        The  fact  that  recognition  may  be  seriously  inter- 
Sered        ruptcd  cvcn  when  the  space-relations  of  objects  are 
even  when      undisturbcd    may   be    brought   out   in   other   ways, 
unchanged.     What  an  unfamiliar  look  there  is,  to  the  unpractised 


Reasons  for 
overlooking 


Fig.  25. 


Experiments  on   Mental  Space  133 

eye,  in  the  photographic  negative  of  even  a  well- 
known  picture  (Fig.  24).  How  many  things  in  it 
escape  us  that  are  noticed  instantly  when  light  and 
shade  are  given  their  accustomed  value  (Fig.  25). 
Here  the  abstract  space-relations  are  certainly  left 
intact;  the  form,  the  outlines,  are  the  same  in  the 
negative  as  in  the  positive,  but  the  mere  variation  of 
the  chiaroscuro  hinders  us  in  singling  them  out,  and, 
for  that  reason  alone,  many  of  the  details  of  the 
picture  are  as  good  as  lost.  Or  if  instead  of  chang- 
ing the  light  and  shade  we  merely  invert  a  familiar 
scene,  the  recognition  of  forms  is  again  perceptibly 
hindered  (Fig.  26).  If  recognition  flowed  from  the 
abstract  geometrical  character  of  the  experience,  it 
ought  to  occur  as  well  after  inversion  as  before.  The 
inversion  does  not  affect  the  shape  or  the  interrelation 
of  things  in  the  scene,  and  yet  the  details  are  for  some 
reason  much  less  readily  disengaged  and  identified. 
If,  moreover,  not  merely  a  part  of  the  visual  experi- 
ence, as  in  this  case,  but  all  things  about  one  were  in- 
verted, it  is  remarkable  how  many  things  in  plain  view 
would  be  overlooked.  Under  these  circumstances 
one  may  not  know  his  next-door  neighbor,  and  his 
home  village  may  seem  as  strange  as  a  foreign  land. 
These  examples  have  been  multipHed  to  show  that 
our  recognition  of  objects  depends  upon  many  factors, 
and  that  the  objects  may  appear  strange  to  us  even, 
when  their  abstract  form  is  all  the  while  what  we  How  much 
have  been  accustomed  to.     The  mere  resetting  of  the  ^^^^'  "^^^"^ 

°  we  pass  to  an 

old  form  makes  it  unknown.^     And  yet  the  resetting  absolutely 

new  sense ! 
^  An  interesting  case  from  a  totally  different  realm,  where  recogni- 
tion would  at  first  sight  appear  to  be  aided  by  novelty  of  setting,  occurs 


134 


Experimental  Psychology 


The  argu- 
ment that 
sight  origi- 
nally is  non- 
spatial  thus 
falls. 

Evidence 
from  Franz's 
case. 


in  the  illustrations  just  given  is  as  nothing  compared 
with  the  reappearance  of  tactual  shapes  in  visual 
materials  never  before  experienced.  The  sifting  out 
of  the  common  elements  in  two  kinds  of  experience 
so  closely  akin  as  upright  and  inverted  vision,  or  as  a 
positive  and  negative  arrangement  of  light  and  shade, 
must  be  the  merest  child's  play  in  comparison  with 
the  perplexities  of  one  just  attaining  sight.  The  very 
difficulty  in  analyzing  the  new  experience,  in  select- 
ing points  of  attack,  and  in  discerning  what  is  sig- 
nificant and  what  is  not,  in  the  endless  confusion  of 
light  and  shade  and  color  —  this  would  certainly 
account  for  the  failure  of  those  surgically  operated 
upon  to  recognize  famiUar  objects  by  sight  alone. 
The  main  argument  for  the  non-spatial  character  of 
vision  thus  falls  to  the  ground.  For  the  failure  to 
recognize  f amiUar  things  by  the  newly  attained  vision, 
which  is  the  main  evidence  adduced,  can  well  be 
explained  in  other  ways. 

And  this  conclusion  that  sight  is  a  space-sense  is 
supported  by  the  results  of  Franz's  experiments 
already  referred  to.  The  case  he  reports  makes  it 
clear  that  if  the  patient  is  clever  enough ;  if  he  has 
the  requisite  intelligence  and  training,  he  can  recog- 
nize, albeit  with   difficulty,  simple   forms  like  a  tri- 


in  the  Indians'  recognition  of  music.  I  once  heard  the  late  Professor 
Fillmore  say  that  while  among  the  Omahas  he  found  that  only  when 
he  introduced  the  harmonic  "parts"  did  they  recognize  their  songs 
when  played  on  the  piano.  They  failed  to  recognize  them  when 
played  as  simple  melodies,  although  they  themselves  did  not  sing  in 
parts,  but  in  unison.  But  may  it  not  be  that  the  instrumental  harmo- 
nies, in  some  subtle  way,  better  imitated  the  chorus,  and  for  this  reason 
helped  the  recognition? 


Fig.  26. 


Experiments  on  Mental  Space  135 

angle,  a  square,  or  a  circle,  even  at  first  sight.  His 
patient's  remark  that  these  figures  were  not  identified 
until  he  noticed  how  they  would  feel  in  his  finger- 
tips, is  no  evidence  that  the  object  as  perceived  by- 
sight  is  from  the  beginning  unlike  its  tactual  counter- 
part. For,  if  the  two  experiences  were  not  alike, 
how  could  the  sight  of  the  figure  have  suggested  to  \ 
his  finger  tips  how  it  would  feel  before  he  had  actu- 
ally touched  it .?  The  suggestion  here  seems  to  have 
been  clearly  based  on  an  underlying  similarity  in  the 
impressions. 

But  even  when  we  have  reached  the  conclusion  But  which 
that  sight  gives  us  spatial  impressions,  the  old  prob-  ^^spatia/?^°" 
lem  is  still  present,  although  on  a  reduced  scale. 
For  vision  itself  is  a  compound  sense.  It  gives  us  an 
intimate  mingling  of  two  very  different  kinds  of  sensa- 
tions :  the  one  kind  being  pure  impressions  of  light  and 
color,  arising  from  the  action  of  the  nervous  coating  at 
the  back  of  the  eye,  the  retina ;  while  the  other  kind 
are  sensations  of  touch  and  strain,  coming  from  the 
various  muscles  both  within  and  without  the  eye-ball, 
and  from  the  tactile  surfaces  of  the  ball,  socket,  and 
lids.  It  would,  indeed,  be  difficult  to  show  that  impres- 
sions of  Hght  and  color  alone,  without  the  aid  of  these 
tactile  and  motor  accompaniments  of  vision,  would 
have  spatial  form  in  their  own  right.  With  regard  to 
this,  no  crucial  experiment  has  ever  been  made. 

On  the  other  hand  there  is  plenty  of  evidence  that  itr^ortance 
in  our  fully  developed  vision  these  motor  accompani-  °^  ^^^  tactiie- 

J  i^  .-  muscular 

ments  play  a  very  important  r61e.     A  partial  paraly-  element  in 
sis  of  certain  muscles  of  the  eyes  makes  one  incapable  ^^^'°"- 


136 


Experimental  Psychology 


of  judging  correctly  the  position  of  things ;  the  diffi- 
culty of  moving  the  eyes  to  one  side,  for  instance, 
makes  objects  seem  to  lie  much  farther  on  that  side 
than  they  really  are.  Not  only  this  sense  of  the  direc- 
tion of  objects,  but  also  our  feeling  of  their  distance 
from  us  is  largely  due  to  the  feeling  of  movement  and 
strain  in  the  eyes,  and  not  simply  to  sensations  of 
Shown  by       Hght  and  color.      In  regard  to  distance  this  is  well 

the  "pseudo-  demonstrated  by  the  pseudoscope,  an  instrument  con- 
scope  ,  .         .  , 

trived  to  reverse  these  motor  sensations  just  spoken 

of,  by  practically  transposing  the  eyes,  so  that  the 
right  eye  acts  as  if  it  lay  to  the  left  of  the  left  eye. 
In  looking  at  things  through  this  instrument  (one  of 
whose  forms,^  made  with  two  mirrors,  is  shown  in 
diagram  in  Fig.  27)  the  eyes  have  to  converge  more 
for  farther  objects  and  less  for  nearer  ones  —  just 

the  reverse  of  our  normal 
eye  movements;  and  as  a 
result   the  perspective   of 
the  scene  is,  under  favor- 
able conditions,  turned  in- 
side   out.       Far    becomes 
near,  convex  becomes  con- 
cave, and  instead  of  an  object  concealing  what  is 
behind  it,  it  cuts  its  own  outHne  out  of  objects  that 
-"^em  nearer  the  observer,  and  is  seen  through  them. 
'-^  change  of   this  instrument  gives  what  is 
'■'^'reoscope,"  which  has  an  effect  as  if 
''^  placed  abnormally  far  apart 

Mmit  of  Visible  Depth," 
»o  in  the  Scientific  Ameri- 
can, - 


O     O 
Fig.  27.  —  Pseudoscope 
(one  form). 


Experiments  on  Mental  Space  137 


0     O 
c  b     a 

Fig.  28.  —  Telestereoscope 
(one  form). 


—  carries  them,  as  it  were,  to  a  and  c  in  Fig.  28,  in 
contrast  with  their  real  position  at  a  and  b.  It  thus 
intensifies  the  eye  movements  as  we  look  at  different 
portions  of  the  scene,  and  as  a  result  strangely 
increases  the  usual  depth 
effect.  The  perspective  ap- 
pears pulled  out,  accordion- 
like, to  surprising  lengths. 
These  experiments  show 
that  the  relief  which  ob- 
jects have  in  the  fore- 
ground of  vision  —  the 
vivid  plastic  effect  which  the  familiar  stereoscope  so 
well  reproduces  —  is  utterly  wanting  to  beings  whose 
vision  has  mingled  with  it  no  sensations  of  muscular 
movement  and  friction  coming  from  the  cooperation 
of  the  two  eyes.  Many  fish  and  birds,  consequently, 
while  having  two  eyes,  but  without  any  overlapping 
and  conflict  of  the  fields  of  view  of  the  two  eyes, 
must  lack  this  plastic  element  in  their  visual  experi- 
ence. Such  vision  can  give  only  indirect  suggestions 
of  distance  like  that  offered  in  a  skilful  painting, 
but  never  our  unique  impression  of  binocular  depth. 
To  this  extent,  therefore,  we  must  acknowledge 
that  visual  space  is  dependent  on  touch  and  muscular  The  retina  is 
movement.      But   ffranting  that  our  most  vivid  and  ^^p^^^- 

o  o  organ  in  its 

accurate  perception  of  distance  and  of  direction  is  own  right, 
due  to  sensations  which  are  not  purely  of  light  or 
color,  we  need  not  go  to  the  extreme  of  maintaining 
that  distance  and  direction  cannot  be  given  by  light 
and  color  at  all.  The  inner  nervous  coating  of  the 
eye  —  the  retina  —  seems  to  resemble  the  skin  in  its 


138  Experimental  Psychology 

power  to  give  a  vague  feeling  of  outwardness  and  of 
place,  without  the  aid  of  the  other  senses.  When  a 
Effect  of  dis-  surgeon  transplants  a  portion  of  the  skin,  for  some 
tionrofft^"^'  ^^^^®  after  the  operation  things  touching  this  trans- 
planted surface  seem  to  be  in  contact  with  the  body 
in  the  region  where  this  portion  or  skin  used  to  be. 
The  similarity  of  the  space-function  of  the  retina  is 
suggested  by  the  occurrence  of  a  like  phenomenon 
in  vision.  Wundt  has  related  that  a  disease  of  the 
underlying  tissues  in  one  of  his  eyes  caused  portions 
of  the  retina  to  shift  their  place.  The  scene  itself 
seemed  to  suffer  distortion  in  consequence.  Objects 
were  localized  as  if  they  were  stimulating  the  place 
in  the  eye  to  which  these  nervous  elements  had 
hitherto  belonged,  and  all  things  were  seen  awry, 
until  the  dislocated  parts  came  finally  to  act  as  if 
they  had  always  belonged  in  their  new  positions.^ 
As  regards  the  importance  of  movement,  then,  the 
retina  seems  to  be  Hke  the  palm  of  the  hand.  Just 
as  the  hand,  even  when  merely  resting  upon  an  ob- 
ject, obtains  a  vague  sense  of  the  relative  direction  of 
its  different  parts,  and  yet  its  movement  brings  out 
their  positions  more  definitely  and  permits  us  more 
accurately  to  interconnect  them  and  to  cover  a  larger 
area;  so  with  the  eye.  Its  mobility  gives  a  nicety 
and  range  of  space-perception  that  a  motionless  retina 
could  never  attain.  But  the  movements  only  intensify 
and  perfect  what  would  be  there  in  some  degree  with- 
out them. 

Much  more  briefly  must  we  consider  the  evidence 

^  Wundt,  "  Zur  Theorie  der  raumlichen  Gesichtswahrnehmungen," 
Philosophische  Studien,  Vol.  XIV,  p.  i. 


Experiments  on   Mental  Space  139 

for  what  I  have  called  the  visuaUsts'  position.     The  The  visual- 
supporters  of  this  view  would  agree  with  all  that  has  ^f  hfiTthr 
just  been  said  as  to  the  power  of  sight  to  make  us  exclusive 
acquainted  with  space  at  first  hand,  but  would  main-  ^p^^^-^^"^^- 
tain  that  it  is  the  only  sense  that  has   this   power. 
Touch  and  movement,  they  hold,  can  of  themselves 
give  no  feeling  of  space ;  those  who  have  never  seen, 
who  have  been  born  blind,  live  in  a  world  that  is  for 
them,  devoid  of  extension,  —  a  pure  time-world.    This  Accordingly 
doctrine   in   fact  gains    its  adherents  chiefly  among  aJeth'o^ht 
persons  particularly  interested  in  the  life  of  the  bhnd.   to  live  in  a 
Platner,    for    instance,   in    the    eighteenth    century  J^oriV^"^^" 
adopted  this  strange  view;  and  within  recent  years 
Dunan  reports  that  a  number  of  French  officials  in 
charge  of  institutions  for  the  blind  are  convinced  that 
one  who  has  never  seen  has  absolutely  no  sense  of 
space.^     Platner  has  been  quoted  as  if  his  testimony 
were  well-nigh  decisive.     But  he  had,  in    truth,  no 
very  exceptional  opportunities  for  studying  the  prob- 
lem,  and   offers   practically   no   evidence  whatever. 
He  does  little  more  than  to  assert  somewhat  impres- 
sively that  for  three  weeks  he  investigated  the  case 
of  a  blind  man  and  convinced  himself  that  the  blind 
know  nothing  of  space.     Dunan,  on  the  other  hand, 
does  offer  evidence,  but  it  is  evidence  which  after  all 
does  not  make  for  his  conclusion.     He  shows,  for  in- 
stance, that  a  blind  man  does  not  think  of  a  distant 
object  in  the  same  way  that  a  normal  person  does ; 
that  the   perspective  element  must  of  necessity  be 

1  Platner,  Philosophische  Aphorismen,  ed.  1 793-1800,  Vol.  I,  pp.  440 
ei  seq, ;  Dunan,  "  L'espace  visuel  et  I'espace  tactile.  Observations  sur 
des  aveugles,"  R^vue  Fhilosophique,  Vol.  XXV,  pp.  357  et  seq. 


1 40  Experimental  Psychology 

wanting,  for  this  is  a  matter  entirely  of  sight.  What 
we  so  prominently  associate  with  distance,  —  the 
diminishing  size,  the  converging  lines,  the  loss  of 
detail,  the  change  of  color,  —  all  this  must  be  absent 
from  the  blind  man's  picture  of  what  is  remote.  But 
even  so,  we  cannot  conclude  with  Dunan  that  this 
implies  that  such  a  person  has  no  idea  whatever  of 
distance.  The  essential  thing  is  not  that  their  rep- 
resentation should  be  identical  with  ours  and  should 
have  exactly  the  same  associations,  but  that  there 
should  be  any  appreciation  of  distance  at  all.  With 
us,  certainly,  this  appreciation  is  not  inseparably 
bound  up  with  the  perspective  of  lines  and  of  at- 
mosphere. Our  most  vivid  impression  of  the  third 
dimension  is,  in  fact,  independent  of  these.  The 
striking  relief  in  which  objects  stand  that  are  within 
six  hundred  yards  of  us  has  nothing  to  do  inherently 
with  the  factors  upon  which  Dunan  lays  such  stress. 
Within  a  certain  distance  of  us,  as  the  experiment 
with  the  pseudoscope  just  recounted  shows,  an  object 
may  seem  nearer  than  another,  in  defiance  of  con- 
trary suggestions  of  size  or  of  linear  or  aerial  per- 
spective. Therefore  these  latter  are  clearly  not  the 
essence  of  our  feeling  of  distance. 
Rejection  of  There  is  no  evidence  whatever  that  the  bhnd  do 
Dunan  vkw.  ^^^  obtain  something  of  this  same  plastic  sense  of 
the  world  through  movements  of  the  body  and  espe- 
cially of  their  hands  and  arms,  although  the  range 
within  which  they  have  it  must  certainly  be  less 
than  vision  gives  to  us.  If,  on  the  other  hand,  we 
were  to  accept  Platner's  belief  as  correct,  that  the 
world  of  those   born  blind  is  a  spaceless  world,  it 


Experiments  on  Mental  Space  141 

would  be  difficult  indeed  to  explain  the  instances 
where  those  surgically  cured  of  blindness  have  been 
able  to  recognize  simple  forms  by  sight  alone ;  and 
equally  difficult  to  explain  the  rapid  progress  even 
the  others  make  in  familiarizing  themselves  with 
space.  Distance  and  direction  and  size  do  not  appear 
to  be  absolute  novelties  to  these  abnormal  persons. 
Their  real  difficulty  seems  to  be  merely  to  interpret 
the  distances  and  sizes  and  directions  of  their  new 
experience  in  terms  of  their  older,  tactual  life. 

We  may  conclude,  then,  it  seems  to  me,  that  touch  Touch  and 
is  a  spatial  sense  in  its  own  right.     The  visualists,  g^atia/^^^^^ 
like  the  tactualists,  have  a  one-sided  doctrine.    For 
there  is  no  single  exclusive  channel  of  this  experi- 
ence, but  both  sight  and  touch  give  us  a  first-hand  | 
acquaintance  with  the  world  of  extension.  ^ 


CHAPTER  VIII 

THE  HARMONIES  AND   DISCORDS   OF   SPACE  PER- 


with  their  ^E  are  thus  brought  to  the  view  that  the  world  of 

manyincon-  extended  things  comes  in  upon  us  through  at  least 
do^touchai^  two  distinct  channels.^  But  this  conclusion,  conso- 
sight  ever       j^^L^t   as  it  secms  with  common  sense,  brings  a  fresh 

harmonize?       ,.^^       ,        .       .  .  ^  ,  ,    . 

difficulty  m  its  train.  For  we  have  now  to  explain 
how  sight  and  touch,  which  are  fundamentally  so  un- 
like, can  nevertheless  make  us  feel  that  they  are  tell- 
ing the  self-same  story.  When  we  compare  the 
conditions  under  which  each  operates,  there  seems  to 
be  nothing  but  a  series  of  contrasts  between  them ; 
and  yet  the  results  are  somehow  harmonious.  When 
I  hold  a  ball  in  my  hand  it  touches  and  excites  a  large 
surface  of  the  palm  ;  but  when  I  look  at  it,  it  stimu- 
lates a  portion  of  the  sensitive  surface  of  the  eye  no 
larger  than  a  pin's  head.  And  yet  the  ball  I  see 
seems  quite  as  large  as  the  one  I  feel.  Moreover,  as 
I  touch  the  object,  it  affects  my  hand  ;  but  as  I  look  at 
it,  it  influences  a  portion  of  the  body  removed  from 
my  hand,  namely  the  eye.  And  yet,  in  both  instances, 
the  object  seems  to  us  to  be  in  the  same  place.     As  a 

1  That  hearing  is  also  an  independent  spatial  sense  (though  much 
more  limited  in  many  respects)  seems  highly  probable.  Cf.  Pierce, 
Studies  in  Visual  and  Auditory  Space  Perceptiony  New  York,  1901, 
pp.  180  et  seq. 

142 


spatial  Harmonies  and  Discords        143 

final  contrast,  the  image  in  the  eye  lies  in  a  reversed 
direction  from  that  of  the  impression  on  the  hand; 
and  yet  we  see  the  object  as  lying  in  the  same  direc- 
tion that  it  has  for  touch.  In  spite  of  all  these  incon- 
gruities in  the  tactual  and  the  visual  impression,  the 
two  senses  work  in  perfect  harmony  and  show  us  the 
same  world.     How  is  this  to  be  accounted  for  ? 

It  is  sometimes  said  that  there  really  is  no  problem  it  is  no  an- 
here;  that  there  is  no  need  of  showing  how  harmony  t^^Twelre 
can  result  from  such  antitheses,  because  we  are  never  never  con- 
conscious  of  the  minute  image  in  the  "fund"  of  the  retinal im-^^ 
eye.     It  is  true  that  the  retinal  impression  is  not  felt  age. 
in  the  eye,  and  yet  this  hardly  seems  to  me  to  explain 
anything,  but  rather  is  part  of  the  very  fact  that  needs 
to  be  explained.     Why  is  it,  we  may  ask,  that  in  sight  i.  w^hyisthe 
we  do  not  locate  objects  at  the  place  where  the  sense-  pr^^Jlected^^* 
impression   occurs,   while   in  touch   we   do  .•*       Why  while  the 
this   striking   difference  in  our  mental  action  in  the  ^^^^^^  *^"°* 
two  cases  .-*     It  is  certainly  not  because  there  is  some 
native  predisposition  in  the  organs  themselves  to  lo- 
cate their  objects  in  this  different  way.     We  do  not 
do  it  instinctively.     On  the  contrary,  it  is  due  to  ex- 
perience and  associations.     We  learn  that  the  things 
which  give  us  touch  sensations  are  at  the  skin ;  and 
Hkewise  we  learn  that  objects  which  give  us  impres- 
sions of  light  and  color  are  not  at  our  eyes.     When  Causes  for 
a  child  grasps  a  ball,  he  can  pass  his  other  hand  at  J^^^  fouch^*' 
once  over  both  hand  and  ball.     This  independent  ob-  impressions. 
servation  shows  that  the  object  and  the  sensory  sur- 
face lie  in  contact,  and  that  it  is  not  a  case  of  action 
from  a  distance.     The  lips  also  feel  hand  and  ball 
close  together.     And   finally  the   eyes  can  observe 


144  Experimental  Psychology 

them  both  in  the  same  glance.     From  repeated  ex- 
periences of  this  sort  it  becomes  a  fixed  habit  to  feel 
the  object  that  excites  the  skin  as  lying  against  the 
skin  itself. 
Why  visual         But  whcrc,  now,  shall  the  child  locate  the  object 

iTeToTfeit'in  *^^*  ^^  ^^^^  ^     ^^  ^^^^S  against  the  retina   of  the 
the  eye.  eye  ^     If  the  rest  of  experience  supported  such  an 

interpretation,  yes.  But  the  fact  is  that  the  rest  of 
experience  suggests  quite  the  contrary.  In  the  first 
place,  as  the  child  passes  his  other  hand  over  the 
hand  grasping  the  ball,  he  does  not  come  upon  his 
eye  lying  against  them  both.  His  hand  must  make 
quite  a  journey  after  touching  hand  and  ball  before 
it  touches  the  observing  eye.  Moreover,  things  that 
we  know  are  hard  and  heavy  do  not  impede  the 
movements  of  the  eyes  when  we  look  at  them,  while 
the  same  objects  do  check  our  movement  more 
or  less  when  we  touch  them.  And  so  on  ad 
infinitum.  There  are  experiences  enough  and  to 
spare  to  account  for  our  reference  of  the  objects 
away  from  the  surface  in  the  one  case  and  to  the 
surface  in  the  other.  There  is  no  need  of  assuming 
that  in  vision  there  is  an  innate  tendency  to  project 
the  object.  Nor,  on  the  other  hand,  do  we  begin 
with  a  feeling  that  things  are  against  our  eyes,  and 
later  learn  to  project  them. 
Objection  Several  of  those  successfully  operated  on  for  con- 

SSeWkra*"^  genital  cataract  —  Cheselden's  and   one   of   Home's 
etcU,  patients,  for  example  —  did,  it  is  true,  declare   that 

things  seemed  to  touch  their  eyes.  But  this  means 
no  more,  it  seems  to  me,  than  would  our  own  feeling 
on  passing  from  a  dark  room  into  very  dazzling  sun- 


spatial  Harmonies  and  Discords        145 

light ;  something  then  often  seems  to  **  touch  "  our 
eyes,  so  strong  is  the  accompanying  feeling  of  dis- 
comfort and  muscular  contraction.  For  we  must 
remember  that  just  after  an  operation  sight  is  usually 
coupled  with  pain  and  tears  and  muscular  spasms; 
and  since  these  are  naturally,  from  previous  experi- 
ence, felt  as  at  the  eyes,  it  is  little  wonder  that  ob- 
jects should  seem  in  very  contact.  But  Home's 
other  patient  who  suffered  little  and,  indeed,  enjoyed 
the  new  experience  so  much  that  he  could  not  be 
made  to  keep  the  bandages  on  his  eyes,  said  that 
things  did  not  seem  to  touch  his  eyes,~although  he 
could  not  say  definitely  how  far  off  they  were.  In 
all  probability,  therefore,  apart  from  previous  experi- 
ence, we  begin  without  either  projection  of  objects 
into  space,  or  definite  reference  of  them  to  the  sur- 
face of  the  body.  We  have  a  tendency  neither  the 
one  way  nor  the  other ;  we  simply  let  ourselves  drift 
as  experience  itself  carries  us.  If  the  experience  had 
been  radically  different ;  if  the  world  had  been  so 
constructed  that  objects  regularly  aroused  pressure 
sensations  without  coming  in  contact  with  the  skin ; 
and  if  luminous  objects  had  to  come  up  to  the  retina 
in  order  to  arouse  sensations  of  light  and  color,  our 
interpretation  of  these  experiences  would  have  been 
exactly  reversed.  Then  we  should  have  learned  to 
see  things  as  lying  against  our  eyes  and  have  felt  the 
touch  of  them  as  coming  from  a  distance. 

II.  How  can 

there  be  3, 

But  now  as  to  the  harmony  which  the  senses  show  harmony  in 
in  reporting  the  more  exact  direction  and  position  of  ^^s^^'^  ^°  *h® 
things.     For  centuries  a  puzzling  problem  has  been  objects? 


146 


Experimental  Psychology 


Claim  that 
the  inversion 
in  the  eye  is 
useful  and  in- 
dispensable. 


Experiment 
with  revert- 
ing lenses. 


Fig.  29.  —  The  normal  inversion  of  the 
retinal  image. 


to  explain  how  we  can  see  things  right  side  up, 
although  the  image  by  which  we  see  them  is  upside 
down  like  the  picture  on  the  ground  glass  of  a 
photographic  camera  (cf.  Fig.  29).  Some,  however, 
have  taken  the  bull  by  the  horns,  and  declared  that 
this  inversion   of    the  image    really  simplifies    the 

problem  rather 
than  renders  it 
more  obscure. 
They  assert,  para- 
doxically, that  our 
vision  of  things 
as  upright  would 
be  difficult  —  nay,  impossible  —  to  account  for  if  the 
image  in  the  eye  were  not  inverted.  The  mechanism 
of  the  eye,  they  maintain,  is  such  that  it  must  of  neces- 
sity make  us  perceive  objects  as  in  the  reverse  direc- 
tion from  that  of  the  retinal  image.  If  the  image  had 
been  right  side  up,  instead  of  inverted  as  it  now  is, 
this  reversal  in  our  perception  would  still  have  taken 
place,  and  we  should  in  that  event  have  seen  things 
upside  down.  Upright  vision,  according  to  this  doc- 
trine, is  dependent  on  there  being  in  the  eye  an 
inverted  image  of  the  outer  world. 

Recent  experiments,  however,  are  decidedly  against 
this  conclusion.  In  order  to  see  whether  the  inver- 
sion of  the  image  was  really  so  necessary  as  the  ad- 
vocates of  this  view  supposed,  an  observer  wore  a  set 
of  lenses  (as  in  Fig.  30)  that  turned  the  retinal  image 
into  an  upright  position  for  a  considerable  length  of 
time.  The  results  showed  that  an  experience  coming 
from  such  an  upright  image  would  in  time  be  indis- 


spatial  Harmonies  and  Discords         147 

tinguishable  from  our  normal  experience.  The  first 
effect  was  to  make  things,  as  seen,  appear  to  be  in  a 
totally  different  place  from  that  in  which  they  were 
felt.  But  this  discord  between  visual  and  tactual 
positions  tended  gradually  to  disappear;  not  that 
the  visual  scene  finally  turned  to  the  position  it  had 
before  the  inversion,  but  rather  the  tactual  feeling  of 
things  tended  to  swing  into  line  with  the  altered  sight 
of  them.  The  observer  came  more  and  more  to  refer 
his  touch  impressions  to  the  place  where  he  saw  the 
object  to  be;  so  that  it  was  clearly  a  mere  matter 
of  time  when  a  complete  agreement  of  touch  and 
sight  would  be  secured  under  these  unusual  condi- 
tions. And  when  once  the  sight  of  things  and  the 
feeling  of  them  accord  perfectly,  then  all  that  we 
mean  by  upright  vision  has  been  attained.^ 

A  later  experiment  of  a  somewhat  similar  kind^  Experiment 

1  1  A.^     1.  with  project- 

has      shown      that  ..,,-4.    ing  mirrors. 

the  agreement  of 
touch    and    sight 

cansurmounteven  

greater    obstacles  '"-•-. i: 

i-hon      fVif-cp  A         Fig.  30.  — An  arrangement  of  lenses  giving 

tiidii       LiiCbC.         x\  an  upright  retinal  image. 

set  of  mirrors  was 

attached  to  the  body  by  a  light  frame  so  that  the 
observer  viewed  himself  as  from  above  his  own 
head.  By  means  of  screens  on  this  frame,  vision 
was  confined  as  nearly  as  possible  to  the  view  which 

1  A  detailed  account  and  discussion  of  these  experiments  will  be 
found  in  the  Psychological  Review,  Vols.  Ill  and  IV. 

2  Cf.  "The  Spatial  Harmony  of  Touch  and  Sight,"  Mind,  October, 
1899. 


148  Experimental  Psychology 

the  mirrors  gave,  and  these  mirrors  reflected  things 
not  only  out  of  their  proper  direction,  but  gave  them, 
as  well,  a  false  distance  from  the  observer.  Here 
again  the  result  was,  at  first,  an  utter  discord  in 
the  spatial  reports  of  the  two  senses.  The  whole 
body  was  seen  in  a  different  place  from  where  it  was 
felt;  it  was  in  fact  projected  at  a  right  angle  to 
the  front  and  several  feet  away,  as  indicated  by 
the  dotted  outline  in  Fig.  31.     But  the  constant  sight 


,.<f. 


""\.j 

^'-'<- 


>^ kA 


Fig.  31. — Arrangement  of  mirrors  for  projecting  the  body  into 
a  false  direction  and  distance. 


of  the  feet  and  hands,  for  instance,  tended  to  pull 
the  feeling  of  these  members  over  into  the  place 
where  they  were  seen,  so  that,  on  the  third  day, 
there  were  occasions,  especially  during  rapid  walk- 
ing, when  no  conflict  was  felt  as  to  the  place  of 
the  various  impressions.  Such  a  harmony,  it  must 
be  confessed,  was  only  occasional ;  but  that  it  could 
come  at  all,  and  particularly  that  it  came  more  for- 
cibly the  longer  the   experiment  was  tried,  shows 


Spatial  Harmonies  and  Discords        149 

clearly  what   the   harmony  of  the   tactual  and   the 
visual  space-world  consists  in.     The  experiment  in-  what  the 
dicates  that  if  we  were  to  see  a  thing  long  enough  ^^™°n^°^ 
in  any  given  place,  we  should,  sooner  or  later,  also  touch  con- 
feel  it  there.     If  the  world  had  been  so  constructed  ^^^^^  ^"* 
that  we   always    saw  our   bodies   a   hundred    yards 
away  from  our  point  of  view,  our  touch  sensations 
would  undoubtedly  have  taken  this  same  position. 
The  reason  for  it  is  this :  there  is  no  place  in  the 
visual  field  where  we  can  say  beforehand  we  ought 
to  see  something   that  we  happen  to  be  touching. 
Experience  alone  can  teach  us  where  it  will  appear. 
And  similarly,  before  experience  has  guided  us,  there 
is  no  way  of  telling  where  we  shall  feel  an  object^ 
that  we   are   looking   at.      This   is  why  those  who 
are  born  blind  and  are  suddenly  given  sight  make 
such  work  of  touching  the  things  they  see.     They 
grope  and  fumble  and  seem  to  hit  the  mark  solely 
by  chance.     But  once  a  person  has  noted  the  kind  of 
arm  movement  that  will  bring  his  hand  to  what  he 
sees,  then,  when  the  visual  experience  is  repeated,  he 
naturally  expects  that  if  he  repeats  his  former  move- 
ment he  will  again  touch  the  object.     If  he  actually 
finds  the  thing  there,  he  feels  that  touch  and  sight  are" 
in  accord ;  if  he  finds  it  elsewhere,  they  seem  to  dis-  Each  must 
agree.      The   agreement   is,  therefore,  a   matter   of  pe^cTat'ions!''" 
training  and  expectation.     One  can  learn  to  expect 
anything  that  has  been  regularly  experienced.      So 
that  a  harmony  of  touch  and  sight  can  grow  up  under 
the  greatest  variety  of  circumstances,  provided  merely 
that  the  experience  remains  uniform  long  enough  to  , 
develop  fixed  expectations. 


150  Experimental  Psychology 

III.  How  can  As  for  the  size  of  visual  objects  —  that  in  spite  of 
monyat^o'^'  ^^^  minutcncss  of  the  image  in  the  eye,  the  object 
the  size  of  looks  no  Smaller  than  it  feels  —  doubtless  some  en- 
o  jects  thusiast  will  one  day  try  the  experiment  of  wearing 

glasses  that  make  all  things  appear  twice  or  thrice  or 
half  as  large  as  they  normally  do.  But  even  before 
the  fact,  in  the  light  of  the  experiments  already  tried, 
we  can  pretty  safely  say  what  the  outcome  of  such  an 
experiment  would  be.  At  first  the  visual  report  of 
things  would  contradict  the  report  as  given  by  the 
hand,  but  in  time  the  disparity  would  begin  to  pass 
away  and  the  observer  would  become  conscious  of 
less  and  less  incongruity  in  the  two  kinds  of  experi- 
ence. If  continued  long  enough  the  last  vestige  of 
disagreement  would  disappear ;  things  would  seem  to 
be  of  the  same  size  whether  seen  or  touched.  For 
Absolute  size  the  amount  of  surface  that  an  object  covers  in  the 

presslcJITsis  ^y^^  ^^^  ^^^  ^^^^^^  ^^  ^^  ^^^^  ^^^  extent  of  the  object 
unimportant,  as  we  SCO  it.  The  size  of  a  thing  for  us  is  a  relative 
matter ;  it  is  its  extent  as  compared  with  other  things. 
Now  the  image  in  the  eye,  tiny  as  it  is,  gives  all 
things  in  due  proportion;  it  shows  me  my  body  as 
about  the  size  of  my  fellow's,  it  shows  my  arm  as 
smaller  than  my  body,  my  hand  as  smaller  than  my 
arm,  and  so  on.  The  relations  here  are  exactly  the 
same  as  those  that  touch  reports ;  and  so  the  two 
senses  agree  here  also,  in  spite  of  the  strangely  differ- 
ent conditions  under  which  they  operate.  The  all- 
important  thing  is  not  the  absolute  size  of  visual 
The  inter-  images  or  of  touch-perceptions,  but  that  the  rela- 
-eiations  are    ^-jq^s  should  be  kept  intact  —  that  when  touch  reports 

he  essential  '^  ^ 

hing.  a  thing  to  be  half  the  size  of  another,  sight  should 


Spatial  Harmonies  and  Discords        151 

tell  the  same  story.  This  relation  of  things  to  one 
another  is  shown  as  well  upon  one  scale  as  upon 
another.  The  absolute  expanse  of  the  picture  is  of 
no  moment  so  far  as  the  mere  harmony  of  the  space- 
perception  is  concerned,  although  for  other  considera- 
tions it  is  important  that  the  image  should  be  neither 
too  large  nor  too  small.  So  that  here  again  it  is  a 
matter  of  training  and  expectation.  Experience  alone 
can  teach  us  how  much  space  the  object  we  are  touch- 
ing shall  occupy  in  the  visual  field.  Any  other 
amount  of  space  would  do  quite  as  well,  provided  all 
other  things  were  in  proportion.  But  once  our  ex- 
pectation has  become  set;  once  we  have  felt  how 
large  our  hand,  for  instance,  is  and  then  have  seen 
it,  the  two  experiences  stand  for  each  other  there- 
after and  the  two  sizes  seem  identical.  But  they 
would  likewise  have  seemed  identical  if  the  visual 
experience  had  been  tenfold  or  one-tenth  of  what  it 
now  is.  In  all  these  different  aspects  —  whether  it 
be  of  size  or  distance  or  direction  —  custom  and  habit 
are  the  great  forces  which  tend  to  bring  a  harmonious 
result  out  of  the  most  contrary  conditions.     ^ 

But  one  can  dwell  too  exclusively  on  this  concord  The  perma- 
that  seems  to  prevail  in  our  mental  construction  of 
space.  The  experimenter,  in  fact,  is  constantly  run-  sight. 
ning  upon  minor  discrepancies  in  the  reports  of  the 
senses.  For  instance,  the  smooth  edge  of  a  card 
pressed  upon  the  arm  will  feel  shorter  than  it  looks ; 
or  when  the  finger  is  run  along  a  row  of  raised  points, 
such  as  the  blind  use  in  reading,  the  distance  will  in 
many  cases  feel  shorter  than  this  same  stretch  does 


nent  discords 
of  touch  and 


152 


Experimental  Psychology- 


Discord  is 

annulled 
only  when  it 
does  harm. 


Space-per- 
ceptions are 
at  times  non- 
Euclidean. 


Examples. 


when  marked  off  by  the  two  terminal  points  alone ; 
while  vision  gives  just  the  opposite  effect :  the  dotted 
distance  now  seems  longer  than  the  same  stretch  free 
from  dots.^  These  inconsistencies  persist  perhaps 
chiefly  because  they  have  to  do  with  out-of-the-way 
operations,  and  the  errors  are  of  no  practical  impor- 
tance. For  the  spatial  agreement  of  the  senses  goes 
only  so  far  as  is  needed  for  ordinary  conduct.  Nature 
is  no  enthusiast ;  she  does  not  rush  into  the  work  of 
harmonizing  our  space-faculties  as  an  end  in  itself 
and  to  be  carried  out  with  Ruskinian  fidelity  and 
conscience.  The  whole  matter  is  dropped  at  the 
point  where  it  ceases  to  minister  to  the  practical 
aims  of  life. 

But  not  only  does  our  space-experience  thus  have 
its  unfinished  nooks  and  corners,  but  at  times  it  seems 
to  do  violence  to  the  principles  of  at  least  the  older 
geometry.  According  to  Euclid,  for  example,  the 
sum  of  the  angles  around  a  point  is,  when  the  angles 
are  all  in  one  plane,  exactly  equal  to  four  right 
angles ;  and  if  we  enlarge  certain  of  the  angles  about 
this  point  we  do,  by  just  so  much,  diminish  the  re- 
maining angles.  Now  in  our  actual  perception  this 
does  not  always  hold.  In  Fig.  32  the  angle  AOB 
seems  to  be  a  right  angle ;  likewise  COD^  DOEy  and 
EOF)  and  yet  in  the  same  plane  there  remains  over 
and  above  these  an  angular  distance  AOFdirvd.  BOC 
that  is   not  included  in   them.      The   psychological 


1  When  we  take  very  small  distances  for  touch,  say  one  centimeter, 
as  the  total  dotted  distance,  the  illusion  is  in  the  same  direction  as  in  sight. 
Cf.  Robertson,  "*  Geometric-optical '  Illusions  in  Touch,"  Psychological 
Review t  November,  1902. 


spatial  Harmonies  and  Discords         153 


effect  here  is  in  violation  of  our  usual  geometrical 
assumption  that  the  subdivision  of  space  does  not 
alter  its  quantity  ;  for  the  minutely  subdivided  angles 


Fig.  32. 


seem  greater  than  those  not  so  subdivided.  And, 
moreover,  we  see  here  that  the  enlargement  of  two 
of  the  angles  AOE  and  BOD  by  subdivision  does  not 
appear  to  make  them  encroach  upon  the  space  occu- 
pied by  the  neigh- 
boring angles  AOB  ^  X  \  B 
and  EOD.  In  the 
case  of  parallel  lines, 
also,  our  experience 
actually  brings  to- 
gether properties 
that  are  (according 
to  the  Euclidean 
geometry)  impossible.  In  Fig.  33  the  lines  AB  and 
CD  seem  to  have  the  same  general  direction,  and  yet 


A 

\ 

N 

Fig.  33. 

154  Experimental  Psychology 

the  distance  between  them  at  one  end  (AC)  seems 
greater  than  at  their  other  end  (BD))  or  if  there  does 
seem  perhaps  to  be  some  difference  of  direction  in 
the  lines,  it  is  hardly  as  much  as  ought  geometrically 
to  go  with  this  inequality  in  the  apparent  distance 

between  their  ends.  Psycho- 
logically, too,  the  possibility 
of  superposition  is  no  evi- 
dence that  the  figures  will 
be  identical  when  not  super- 
posed. The  accompanying 
forms  (Fig.  34)  seem  of  dif- 
erent  size  and  shape,  and  yet 
a  perfect  coincidence  of  out- 
FiG.  34.  \^  lines  is  possible.   And,  finally, 

of  three  points  lying  in  a  straight  line,  the  middle 
point  may  appear  to  move  at  right  angles  to  this 
line,  and  yet  it  may  not  seem  at  any  moment  to  be 
out  of  line  with  the  other  two  stationary  points.     This 
experiment  may  be  performed  thus  :  if  we  arrange 
the  points  say  vertically  (as  in  Fig.  35)  and  have 
behind  the  middle  one  a  set  of 
short  vertical  bars  mounted  on 
a  drum  that  is  revolving  slowly 
from  right  to  left,  and  we  ob- 
serve fixedly  the  middle  point  ^      ^ 
for   some   time   and    then   sud-                pi^^  ^^^ 
denly  stop  the  passing  bars,  the 
middle  point  as  we  continue  to  look  at  it  will  then 
seem  slowly  to  move  from  left  to  right  while  the  other 
two  points  remain  stationary ;  and  yet  we  can  see  that 
it  remains  all  the  while  in  line  with  these  two  points. 


Illlllll 


Spatial  Harmonies  and  Discords        155 

The  obvious  objection  to  taking  these  exceptional  These 
phenomena  seriously  would  be  that  they  are  mere  illu-  ^"s^^^^^s 

r  J  J  are  mere  illu- 

sions, and  therefore  have  no  bearing  on  the  question  sions. 

of  the  universal  validity  of  mathematics.  For  geome- 
try is  a  science  of  real  space,  the  objector  would  say, 
and  these  aberrations  are  mere  appearances,  not  in 
the  least  indicating  that  actual  space  itself  is  irregu- 
lar or  non-Euclidean.  As  well  might  you  claim  that 
the  law  of  gravitation  is  untrue  because  we  can  dream 
of  objects  falling  away  from  the  earth. 

This,  I  feel,  would  be  a  sufficient  answer  to  any 
one  who  might  cite  these  space-illusions  to  show  that 
geometry  was  untrue  to  the  facts  of  the  outer  world 
as  we  empirically  know  them.  The  character  of  the 
outer  world  —  of  "real"  space  —  is  not  affected  by 
these  inner  vagaries  of  our  sense-perception. 

But  it  would  seem  to  me  that  the  illusions  in  ques-  Yet  even  niu- 
tion  have  a  bearins:   upon  the  validity  of  the  tradi-  sionshavea 

*=*        ^  ^  -'        _  bearing  on 

tional  geometry  in  any  possible  experience  —  the  Kant's  doc- 
question  with  which  Kant  has  dealt  so  profoundly  in  geometry. 
his  "  Transcendental  ^Esthetic."  His  well-known 
position  is  that  geometry  must  of  necessity  hold  true 
universally  because  its  laws  are  somehow  involved 
in  the  very  structure  of  our  sense-perception,  and, 
consequently,  that  it  would  be  impossible  for  us  to 
have  any  experience  without  impressing  these  laws 
upon  it.^     For   one  who  would   gain   this   pitch   of 

1  The  only  direct  reference  to  illusions  and  to  their  possible  bearing 
that  I  can  lay  my  hands  on  in  Kant,  is  the  meagre  and  unsatisfactory 
statement  in  the  Anthropologic  (Hartenstein,  p.  457)  that  they  are 
Erscheinungen  and  not  a  part  of  Erfahrung^  and  apparently  that  ends 
them. 


156 


Experimental  Psychology 


They  are  a 
kind  of  space- 
experience. 


To  avoid  the 
difficulty 
from  illu- 
sions, expe- 
rience must 
be  under- 
stood as  of 
unlimited 
duration, 


and  as  a 
selected  set 
of  percep- 
tions. 


certainty  for  geometrical  truths,  the  space-illusions  in 
question  would  seem  to  deserve  a  little  more  consid- 
eration. They  can  hardly  be  ruled  out  of  court  at 
once  because  they  are  subjective  and  illusory,  for  as 
illusions  they  are  a  kind  of  experience.  And  if  our 
sense-experience  can  in  special  instances  depart  from 
the  principles  of  geometry,  this  might  cast  some 
doubt  upon  the  assumption  that  any  possible  experi- 
ence would  of  necessity  conform  to  Euclid. 

Our  anti-geometric  space-perceptions  show  at  least 
this  much,  that  if  the  older  geometry  is  to  remain 
logically  valid,  space-experience  must  be  understood 
as  including  more  than  the  mere  sum  of  impressions 
that  is  contained  in  any  limited  stretch  of  time,  and 
more  than  the  mere  sum  of  impressions  gathered  in 
even  a  practically  unlimited  duration.  The  "  experi- 
ence "  of  five  minutes  may  contradict  the  traditional 
geometry,  but  hardly  the  experience  of  many  years. 
And  what  we  call  the  experience  of  this  longer  period 
is  after  all  a  kind  of  idealization  of  what  we  have 
gone  through.  We  do  not  give  equal  weight  and 
value  to  all  perceptions  alike.  On  the  contrary,  we 
become  impressed  with  the  need  of  system  and  har- 
mony, and  we  subordinate  and  neglect  those  percep- 
tions of  space  that  do  not  accord  with  the  more 
perfect  plan.  If  experience  in  this  selective  sense 
conforms  to  our  geometrical  theorems,  the  conformity 
must  not  be  understood  as  due  to  the  psychological 
character  of  our  sense-perception  in  each  of  its  par- 
ticular acts.  Every  single  piece  of  space-experience 
does  not  come  with  the  laws  of  geometry  stamped 
upon  it.     Only  in  so  far  as  our  particular  perceptions 


spatial  Harmonies  and  Discords        157 

are  brought  together  into  an  ideal  system,  and  those 
perceptions  that  refuse  to  conform  are  ruthlessly  cut 
off,  —  only  with  this  meaning  of   spatial  experience 
would  there  be  no  conflict  between  psychology  and 
the  older  geometry.     What  we  call  the  experience  of  "Real" space 
"  real "  space  is  consequently  a  kind  of  idealization  or  ^J^^e  X^^' 
purified  experience  obtained  after  sifting  out  and  dis-  ized. 
carding  those  perceptions  that  are  practically  unreli- 
able.    Practical  utility  —  the  idea  of  interrelating  our 
objects  so  that  they  may  serve  as  the  safest  guide 
for  conduct  —  is   thus   a   most  important  factor  in 
making  this  ideal  construction  of  space. 


The  illusions  we  have  been  considering  have  also  is  real  space 

a  social  coi 
struction  ? 


a  further  interesting  bearing  on  the  psychology  of  a  social  con 


real  space  and  of  the  real  world.  At  the  present 
day  there  is  a  strong  tide  in  the  sociaHstic  direction. 
The  interaction  and  friction  of  social  life,  rather 
than  the  inevitable  inner  development  of  the  individ- 
ual or  the  interaction  between  the  individual  and  his 
impersonal  surroundings,  are  being  more  and  more 
emphasized  not  only  in  ethics  and  sociology,  but  in 
psychology  and  even  in  metaphysics.  The  real 
world,  the  external  spatial  reality,  for  each  of  us, 
according  to  this  modern  tendency,  is  that  portion 
of  our  total  experience  that  is  found  to  be  common 
to  us  and  our  fellow-men.  What  is  over  and 
above  this  common  stock  is  judged  to  be  subjec- 
tive and  "  internal."  But  these  space-illusions  show  The  social 
that  too  much  stress  can  be  laid  on  our  collective  or  ^^^l  blen^^^*^ 
social  experience  as  the  test  of  what  exists  in  "real"  made  too 
space ;  it  is  not  the  absolute  and  final  test,  after  all.  ^^^  ° ' 


158  Experimental  Psychology 

For  the  malperceptions  cited  above  are  common  in 
some  degree  to  all  normal  persons,  and  judged   by 
this  standard  we  should  have  to  admit  that  real  space 
had  variable   mathematical   features,  conforming   at 
one  moment  to  certain  elementary  laws,  and  at  the 
Manyiiiu-      next  instant  defying  them.     As  far  as  the  observa- 
meettws^       tion  of  a  number  of  persons  goes,  the  two  outlines  in 
test  Fig.  34  would  have  to  be  considered  as,  in  reality, 

both   identical  and   widely   divergent,   or  as  having 
these    characteristics    in    rapid    succession.       Such 
normal   illusions   show  that   the   properties   of   real 
space  or  of  real  objects  are  reached,  not  by  different 
individuals  unconsciously  comparing  notes,  and  giv- 
ing a  heightened  importance,  a  peculiar  reality,  to 
those  occurrences  that  are  common  to  all  (though 
this   may  be   of    great  influence   as   a   cooperating 
The  criterion  factor),  but  that  cach  individual  has  within   him  a 
div?dua/^'     Standard   by  which   to    detect   even   those   illusions 
that  beset  the  race.      He  can  judge  his  particular 
impressions    in    the    light    of    the    system    of    his 
experience ;  and  "  reality "  is  what  emerges  from  a 
kind  of  interaction  and  self-checking  of  his  various 
sense-perceptions.^     The  distinction  between  reality 
and  illusion   thus   is   not   an   exclusively  social  dis- 
And  thereby    tinction.     Evcn  the  testimony  of  the  senses  of  others 
iifusronseven  ^'^  ^°^  bring  one  to  a  belief  in  the  reality  of  any- 
of  the  race,     thing  that   runs   counter   to   this   less  tangible  and 
yet  more  stable  reality  that  is  adjudged  to  lie  be- 
hind his  own  and  his  neighbors'  direct  sensible  im- 
pressions. 

1  For  the  more  detailed  discussion  of  the  way  we  test  and  detect 
illusions,  see  pp.  108  et  seq. 


spatial  Harmonies  and  Discords         159 

Our  personal  and  immediate,  as  well  as  our  social,  Natural 
experience  of  space,  then,  never  perfectly  conforms  anrouTcon- 
to  our  ideal,  or  to  the  "reality,"  of  space;   it  is  a  sdousness 
more  or  less  imperfect  adaptation.     But  if  we  speak  ®^^p^^®* 
of  adaptation,  and  of  natural  selection  as  part  of  the 
machinery  by  which  the  development  has  probably 
been  brought  about,  so  that  those  individuals  who 
did  not  bring  their   senses   into  harmonious  spatial 
cooperation  were  distanced  in  the  race,  it  must  not 
be  supposed  that  this  completely  explains  the  mental 
process  here.     For  our  consciousness  of  extension  is 
a   fact   that  resists   all   further   analysis;   it  cannot 
be  "  deduced  "  from  some  earlier  mental  condition  in 
which  extension  does  not  exist. 

The  attempt  has  been  made  to  show  that  extension  is  Extension 
a  necessary  result  of  our  having  different  experiences  gq^ai^nt  to 
at  the  same  time ;  that  if  a  number  of  impressions  are  simultaneity, 
to  be  held  together  and  at  the  same  time  kept  distinct, 
they  will  inevitably  cease  to  have  a  purely  temporal 
connection  and  will  become  spatial.     For  time,  it  is 
claimed,  has  but  one  dimension ;  it  has  length  without 
breadth,  and  in  it  experiences  can  come  only  in  sin- 
gle file.     As  soon  as  impressions  coming  together  are 
also  distinguished,  they  are  then  felt  as  side  by  side, 
and  this  is  what  we  mean  by  extension.     Space,  then, 
according  to  this  view,  is  the  necessary  outcome  of 
simultaneous   impressions    distinguished    and   made 
into  a  system. 

The  fallacy  in  this  reasoning  would  perhaps  not  be  Music  as  a 
so  evident  if  we  had  no  ears.     For  our  appreciation  ^'^P^°°^' 
of   music  shows  that  synchronous  sense-impressions 
may  be  organized  into  a  very  definite  system,  which 


i6o 


Experimental  Psychology 


Extension  is 
psychologi- 
cally irre- 
ducible. 


At  what  stage 
of  develop- 
ment does  it 
appear  ? 


has  no  essential  extension  whatever.  In  listening  to 
a  great  orchestral  composition  it  is  true  that  there  is 
usually  some  hint  of  space-relation.  The  sounds  of  the 
different  instruments  seem  to  come  from  more  or  less 
different  directions,  and  to  be  in  varying  degrees  vo- 
luminous. But  these  associations  seem  to  be  quite 
fortuitous  and  are  not  essential  to  the  structure  and 
beauty  of  the  piece.  For  our  space-suggestions  de- 
tract, if  anything,  from  our  clear  perception  of  the 
music,  which  is  a  structure  merely  of  duration,  in- 
tensity, and  pitch.  So  that  our  appreciation  even  of 
a  single  musical  chord  is  evidence  that  time  itself  has 
more  than  one  dimension,  and  allows  mental  impres- 
sions to  come  abreast.  Consequently  it  cannot  be 
urged  that  our  perception  of  space  is  a  necessary 
outcome  of  sensations  coming  together  and  yet  re- 
maining distinct.  Harmony  and  discord  are  not  ex- 
tension. In  fact,  space  cannot  be  reduced  to  a  mere 
association  of  non-spatial  sensations.  For  any  mere 
addition  of  unextended  things  could  no  more  be 
equivalent  to  space  than  a  sum  of  zeros  could 
produce  a  quantity. 

Space  as  a  psychological  fact  is  therefore  a  unique 
addition  to  the  mere  quality,  intensity,  and  dura- 
tion of  our  impressions,  although  it  is  dependent  on 
these  factors.  Just  at  what  point  in  our  mental 
development  this  peculiar  factor  enters,  is  not  known. 
Professor  James  and  Dr.  Ward  are  of  the  opinion 
that  extension  or  voluminousness  is  inherent  in  all 
sensations,  and  consequently  must  have  been  there 
from  the  very  start.  In  this  they  may  or  may  not 
be  right;  for  it  is   impossible   as  yet  to   know  the 


spatial  Harmonies  and  Discords  i6i 

facts.  No  direct  examination  can  be  made  of  the 
sensations  of  creatures  at  the  earliest  stage,  and  their 
reactions  are  at  best  ambiguous.  Jennings's  excellent 
experiments  on  Paramecia  ^  show  that  these  unicellu- 
lar creatures  give  the  same  machine-like  response 
regardless  of  the  place  where  they  are  stimulated. 
They  back-water  and  turn,  always  in  the  one  direc- 
tion, no  matter  from  what  point  the  excitation  comes. 
So  that  there  is  no  positive  evidence  that  they  appre- 
ciate the  position  or  direction  of  things.  Another 
unicellular  organism,  Stentor^  however,  gives  most 
varied  responses  to  different  stimuli,  and  moves  in 
different  directions  according  as  it  is  gently  touched 
upon  one  or  another  side. 

But  if  by  the  word  "sensation"  we  intend  to  desig-  Sensations, 
nate  something  absolutely  unorganized  and  elemental, 
—  the  simple  material  of  our  mental  life,  without  form  "pure, 
and  void,  —  then  the  doctrine  that  even  our  earliest 
mental  impressions  are  extended,  simply  means  that 
a  pure  sensation  never  exists,  not  even  at  the  very 
beginning;  that  an  absolutely  formless  and  disor- 
ganized impression  is  an  idol  of  the  psychological 
cave.  For  voluminousness  in  a  sensation  implies 
that  the  thing  is  complex ;  that  there  are  differences 
held  together  in  some  sort  of  space-relation,  vague 
though  it  be.  If,  then,  the  sensations  of  an  infant 
long  before  birth,  or  of  the  protozoan,  have  in  them 
the  "  quality  of  extensity,"  these  sensations  have  form 

1  Jennings,  "The  Psychology  of  a  Protozoan,"  American  Journal 
of  Psychology,  July,  1899,  with  the  references  there  to  his  other  articles. 
For  an  account  of  his  latest  experiments  on  Stentor  and  Vorticella,  see 
the  American  Journal  of  Physiology,  October,  1902, 


if  extended, 
are  not 


1 62  Experimental  Psychology 

or  arrangement,  and  are  therefore  not  utterly  disor- 
ganized mental  stuff,  ox  pure  sensation.  ^ 
They  prob-  From  the  analogy  of  the  body  we  should  certainly 
ganizTd  from  ^^P^^t  Something  like  this,  —  that  the  mind  too  would, 
the  begin-  from  the  beginning,  be  organized.  For  the  body, 
"^"^*  even  in  the  earliest  single-cell  form,  is  never  abso- 

lutely simple  and  undifferentiated;  it  is  always  a 
union  of  different  parts.  Why,  then,  should  we  as- 
sume that  the  mental  life  is  less  complex }  If  there 
is  any  truth  in  the  doctrine  of  the  correspondence  be- 
tween physical  and  mental  characteristics,  the  psychic 
life  even  at  its  earliest  stage  consists  in  some  kind 
of  organization  of  sense-impressions. 
But  the  To  infer  from  the  analogy  of  the  body  that  the 

neeTnotbe"    "^^^tal   materials   are   never   quite   **raw,"   but   are 
spatial.  already  to   some   extent  worked   up,  by   no   means 

determines  what  is  the  form  of  that  earliest  mental 
life.  It  simply  implies  that  it  has  some  organization 
or  other,  without  deciding  however  that  it  has  this 
special  and  particular  form  of  space.  For  there  are 
many  other  conceivable  forms,  such  as  the  mere  time- 
form,  or  perhaps,  simpler  still,  mere  sense  of  qualita- 

1  Ward,  of  course,  would  quite  agree  with  this  (cf.  his  Naturalism 
and  Agnosticis7}t,  Vol.  II,  pp.  112,  and  following),  and  James,  too 
(cf.  his  Principles  of  Psychology^  Vol.  II,  pp.  3,  4).  But  if  pure  sensa- 
tions are  an  abstraction,  as  James  says  (and,  the  present  writer  feels, 
correctly),  why  should  he  speak  of  their  being  "realized  in  the  earliest 
days  of  life"  {op.  cit.^  Vol.  IT,  p.  7)  any  more  than  in  adult  life? 
Sensation  is,  of  course,  present  all  through  life,  but  only  as  an  abstract 
aspect  of  experience.  Relatively,  of  course,  it  may  be  more  prominent 
in  infancy,  but  never  absolutely  "realized."  We  should  hardly  say, 
for  instance,  that  the  abstraction  of  surface  without  volume  is  realized 
in  a  sheet  of  paper  but  not  in  a  block  of  wood  (cf.  note  on  "  Matter  " 
and  "Form,"  p.  231  of  this  book). 


spatial  Harmonies  and  Discords  163 

tive  contrast,  that  might  well  precede  and  lead  up  to 
this  more  complex  fact  of  spatial  feeling.  This  is  a 
question  of  fact  that  cannot  be  settled  by  the  a  priori 
method.  For  there  is  no  logical  necessity  that  our 
sensations  should  be  extended  at  the  very  start  — 
such  a  necessity,  for  instance,  as  that  sensations 
should  have  some  intensity  if  they  are  to  be  experi- 
enced at  all.  And  when  we  say,  with  the  Kantians, 
that  our  experience  of  extension  is  due  to  some  inner 
activity  of  the  mind,  it  does  not  seem  to  me  that  we 
need  assume  that  this  particular  activity  is  always  in 
evidence,  any  more  than  that  the  categorical  impera- 
tive is  especially  manifest  in  the  earthworm  or  the 
oyster.  But  whether  it  is  always  there,  as  James  and 
Ward  suppose,  or  only  appears  at  some  later  stage 
in  the  mental  development,  its  presence,  in  either 
event,  is  an  irreducible  fact,  and  not  to  be  regarded 
as  an  inevitable  outcome  of  the  merely  temporal 
arrangement  of  our  sensations. 

But  here  the  consideration  of  our  topic  must  close.   Psychology 
It  is  already  clear  that  the  psychology  of  space-per-  ^"^  e^j.^qugs. 
ception  passes  insensibly  into  the  metaphysical  realm,  tions  of 
and  into  that  region  we  must  not  attempt  to  follow  it. 
An  effort  has  here  been  made  to  keep  at  least  within 
sight  of  the  more  experimental  aspects  of  the  case,  — 
the  way  our  minds  obtain  a  picture  of  the  expanse  of 
the  world,  the  senses  on  which  we  depend  for  this,  the 
hints  and  clews  by  which  we  find  out  the  place  and 
size  and  shape  of  things,  and  how  out  of  the  confused 
and  contradictory  data  there  comes  a  consistent  pano- 
rama of  the  world.     We  obtain  in  this  way  some 
hint  of  how  this  strange  power  within  us  works,  but 


space. 


164  Experimental  Psychology 

cannot  after  all  by  any  of  these  means  account  for  it 
or  derive  it  from  deeper  causes.  For  the  psychologist 
it  remains,  in  its  origin,  one  of  the  ultimate  processes 
of  our  mental  life,  like  our  sense  of  temporal  se- 
quence or  of  beauty,  or  our  power  of  taking  interest 
in  things,  or  of  exercising  will.  Whether  it  must  of 
necessity  be  present  in  all  minds,  or  whether  if  it 
were  present  it  would  reach  the  same  results  as  in 
our  case,  psychology  is  unable  to  say.  And  although 
it  is  a  power  which  lies  so  deep  within  us,  yet  it 
seems  less  central  to  the  mind  than  many  of  our  other 
powers.  It  has  not  the  same  moral  place  in  us  that 
memory  or  judgment  or  conscience  has.  For  this 
reason  it  is  treated  lightly  by  the  mystics,  as  being  but 
an  outer  garment  of  the  mind,  a  mere  external  sym- 
bol of  our  deeper  spiritual  states. 


CHAPTER   IX 

MEMORY  AND   THE   INFLUENCE   OF   TIME 

If  we  could  thoroughly  understand  memory,  the  Memory,  if 
rest  of  the  mind  would  give  us  little  trouble ;  for  this  ^"uid'^ake 
one  field  practically  involves  all  the  problems  of  psy-  all  clear, 
chology.  There  is  often  a  temptation  to  pass  over  it 
lightly  as  a  mere  illustration  of  habit  or  of  association ; 
and  in  the  chapters  on  unconscious  ideas  I  may  have 
given  the  impression  that  there  seemed  to  me  to  be 
nothing  more  to  it  than  a  mere  repetition  of  a  pre- 
vious mental  act.  But  we  must  now  do  justice  to 
memory  and  point  out  the  marvellous  intricacy  of  this 
famihar  function.  After  we  have  done  our  best  to 
simplify  it  and  have  regarded  it  as  merely  the  return 
of  a  former  idea,  we  discover  that  there  is  a  flavor 
and  meaning  about  our  memories  which  still  remains 
unexplained.  The  peculiar  backward  look  which 
our  recollections  have  is  something  over  and  above 
their  mere  return.  Many  of  our  ideas  return,  but 
they  have  no  familiarity,  we  do  not  recognize  them; 
they  mean  nothing  historical ;  they  are  not  memories, 
therefore.  So  that  a  memory  is  a  peculiar  type  of 
recurrent  idea  that  is  somehow  greeted  as  a  record 
of  the  past.  Moreover,  it  is  difficult  to  explain  our 
confidence  that  memories  have  historic  truth  —  to 
discover  what  it  is  that  permits  us  to  recognize  them 

165 


i66 


Experimental  Psychology 


The  field  of 
experiment 
here. 


as  copies  of  what  has  gone.  In  looking  at  the  por- 
trait of  a  friend  we  can  say  that  it  is  a  good  likeness 
because  we  can  compare  it  with  the  man  himself  or 
with  our  recollection  of  him.  But  when  we  recognize 
our  memories  as  true  copies  of  the  past,  we  have  not 
the  past  itself  there  nor  some  other  copy  of  it  with 
which  to  compare  them.  And  yet  the  recognition  is 
ready  and  accurate.  Through  memory,  indeed,  the 
mind  seems  to  be  not  only  in  the  time-stream,  but  also 
outside  and  around  it,  looking  down  on  both  past  and 
present  as  from  some  point  remote  from  both. 

Into  this  deeper  side  of  memory  our  experimental 
studies  have  hardly  gone ;  they  are  confined  more  to 
an  investigation  of  the  way  our  ideas  fade  with  time 
and  of  other  changes  they  undergo,  and  of  the  differ- 
ent kinds  of  memory  we  possess.  In  such  matters 
as  these,  most  interesting  work  has  been  done,  and  of 
that  I  shall  try  to  give  a  brief  report. 


Ebbing- 

haus's 

studies. 


His  method 


The  experiments  of  Ebbinghaus  ^  were  the  pioneer 
studies  of  this  kind  ;  and  one  of  the  principal  prob- 
lems that  he  set  before  him  was  to  determine  the  law 
according  to  which  forgetfulness  takes  place.  Com- 
mon experience  makes  it  clear  that  time  is  of  course 
an  important  factor  in  forgetting ;  that  as  time  elapses 
we  forget  more  and  more.  The  most  interesting  of 
Ebbinghaus's  experiments  had  as  their  object  the 
determination  of  the  varying  rate  at  which  this  loss 
takes  place.  His  method  of  investigation  was  certainly 
unique.  He  worked  with  a  large  number  of  nonsense 
syllables  made  for  the  occasion  by  putting  together, 

1  Ebbinghaus,  Ueber  das  Gedachtnisst  Leipzig,  1885. 


Memory  and  the  Influence  of  Time      167 

haphazard  in  each  case,  a  vowel  between  two  con- 
sonants,—  like  tuly  miUf  baf,  cug^jat^  —  and  heroically 
learned  these  by  heart.  He  first  found  how  many 
times  on  an  average  he  must  read  over  a  Hst  in  order 
to  be  just  able  to  repeat  it  without  error,  from  memory. 
A  certain  length  of  time  was  allowed  to  pass,  and  then 
of  course  the  list  could  not  be  correctly  recited ;  it  had 
to  be  re-read  several  times  before  it  was  restored  to 
the  point  where  it  could  just  be  recited  once  without 
mistake.  The  number  of  re-readings  thus  required 
to  restore  it  to  its  original  clearness,  compared  with 
the  number  required  to  learn  the  list  the  first  time, 
gave  some  measure  of  the  degree  of  forgetfulness 
that  had  occurred  in  the  interval.  By  varying 
this  interval  all  the  way  from  twenty  minutes  to  a 
month,  and  carefully  noting  the  difference  in  the 
result,  an  interesting  table  was  obtained  of  the  vary- 
ing speed  at  which  oblivion  comes  on.  Ebbinghaus  and  results, 
found  that  in  a  single  hour  over  one-half  of  what  he 
had  learned  had  been  forgotten ;  after  eight  hours 
three-fifths  was  gone;  after  twenty-four  hours,  two- 
thirds  ;  after  six  days,  three-fourths ;  after  a  month, 
four-fifths ;  or,  in  other  words,  more  was  forgotten  in 
the  first  hour  than  in  all  the  weeks  succeeding.  We 
might  represent  his  results  by  the  accompanying 
curve  (Fig.  36),  in  which  the  slant  indicates  the  rate 
at  which  forgetfulness  ensues,  the  distance  on  the  hori- 
zontal line  representing  the  passage  of  time.  At  first 
the  slant  is  well-nigh  perpendicular,  the  descent  being 
very  sudden,  and  then  becomes  ever  more  gradual. 

The    absolute  values    obtained    by   these    experi-  Their  signifi- 
ments   have   no   especial    significance.      They   must 


cance. 


i68 


Experimental  Psychology 


not  be  understood  to  mean  that  in  every  case,  regard- 
less of  the  materials  with  which  we  are  dealing,  we 
forget  in  the  first  hour  fully  one-half  of  anything  we 
learn.     Allowance  must  first  of  all  be  made  for  dif- 


L 


8.8 


24 


48 


744 


Fig.  36.  —  Curve  showing  the  rate  of  forgetfulness,  according  to  Ebbing- 
haus's  experiments.    The  values  of  the  abscissas  represent  hours. 

ference  of  materials ;  some  things  are  more  fascinat- 
ing than  nonsense  syllables;  they  take  a  more  vital 
hold  of  us,  and  consequently  fade  away  at  a  much 
slower  rate.  And  of  course  different  absolute  values 
in  the  results  are  always  obtained  with  different  per- 
sons. Some  are  more  tenacious  of  a  given  kind  of 
fact  than  others  are.  Ebbinghaus's  experiments  just 
described  had  largely  to  do  with  the  particular  power 
to  repeat  a  series  of  muscular  acts,  —  of  articulatory 
movements ;  and,  in  this,  "  ideas  "  and  consequently 
memory  as  a  mental  act  doubtless  played  some  part, 
although  probably  a  subordinate  one.  But  in  experi- 
ments where  the  recollection  has  to  deal  with  more 
strictly  mental  things  —  where  a  person  has  to  pass 
judgment  on  an  impression  given  several  minutes 
before  —  the  results  are  probably,  here  also,  in 
accord   with    Ebbinghaus's    general  principle.      For 


Memory  and  the  Influence  of  Time      169 

short  lapses  of  time,  however,  —  for  a  few  seconds,  — 
as  I  shall  point  out  later,  the  behavior  of  memory  is 
by  no  means  so  uniform  and  simple.  Only  the  larger 
relations  in  Ebbinghaus's  results,  therefore,  are  sig- 
nificant and  universal,  namely,  that  the  clearness  of 
our  recollections  fades  away  according  to  a  law  of 
diminishing  or  retarded  speed,  whatever  the  speed 
itself  may  be.  So  that  in  the  life  history  of  ideas 
the  probability  of  long  continuance  is  the  greater  the 
longer  the  idea  has  already  been  able  to  hold  its  own. 
Anything  that  is  not  early  devoured  by  time  has  a 
fair  chance  for  sublunary  immortality. 

Now,  this  rapid  and  then  more  gradual  blurring  of  Themuta- 
our  impressions  as  time  goes  by  must  not  be  confused  ^^^^^  °^°^^ 
with  the  actual  distortion  which  events  often  undergo 
in  memory.  Memory  is  often  thought  of  as  illustrat- 
ing the  constancy  of  our  ideas.  We  speak  of  things 
as  indelibly  stamped  or  graven  on  the  mind,  or  liken 
memory  to  a  gallery  where  the  past  is  preserved  in 
lasting  pictures.  In  discussing  the  arguments  for 
unconscious  ideas,  I  have  already  criticised  this  view, 
chiefly  on  logical  grounds,  because  of  a  certain  inco- 
herence in  the  view  itself.  Our  ideas  are  not  solid 
things  that  exist  during  forgetfulness,  but  are  acts 
which  in  many  cases  we  may  repeat  and  re-create  as 
occasion  calls.  The  same  truth  is  enforced  in  another 
way.  P'or  if  ideas  were  actually  stored  up  in  memory 
as  permanent  and  stable  realities,  still  existing  during 
the  interval  of  forgetfulness,  we  might  expect  them 
usually  to  appear  unchanged  as  we  recalled  them  at 
different  times.  But  there  is  often  the  greatest  con- 
trast between  my  present  recollection  of   an  event 


lyo  Experimental  Psychology 

Memory  and  my  recollection  of  it  some  moments  hence.  The 
anddistorts.  ^ncmory  not  only  grows  less  clear,  but  it  actually 
tells  a  different  story  as  time  proceeds.  Now  there 
is  in  psychology  a  frequent  confusion  of  these  two 
independent  facts  of  memory,  —  the  fact  of  f orgetf ul- 
ness  in  the  sense  of  blurring,  and  of  forgetfulness 
in  the  sense  of  distortion.  We  are  at  first  naturally 
tempted  to  represent  forgetfulness  merely  after  the 
manner  of  a  light  that  fades,  or  of  a  substance  that 
evaporates  or  melts  away.  If  the  latter  figure  of 
speech  represented  the  facts,  there  would  most  nat- 
urally be  a  change  in  the  quantity  of  objects  as  we 
forgot  them.  A  half-forgotten  house  might  be  but 
half  the  size  of  the  same  house  fully  remembered. 
Or  a  fire  in  memory  would,  perhaps,  give  out  but  a 
fraction  of  the  warmth  that  we  enjoyed  as  we  sat 
beside  it ;  a  recalled  pound  might  weigh  but  an  ounce, 
and  so  on. 
Someexperi-  Absurd  as  all  this  sounds  to  the  unbiassed  mind, 
there  have  been  a  number  of  experimental  facts  to 
encourage  the  view  that  forgetting  was  equivalent  to 
a  diminution  of  the  intensity  or  size  of  the  original 
impression.  Thus  it  is  true  that  objects  are  judged 
to  be  of  quite  different  quantity  according  as  they 
are  sensibly  present  or  are  only  recalled.  Sounds, 
for  instance,  are  often  judged  to  be  less  loud  as 
they  fade  into  the  past.  If  we  listen  to  the  stroke 
of  a  faUing  ball  (dropped,  say,  from  the  upper 
magnetic  holder  of  the  instrument  in  Fig.  37),  and 
some  moments  later  a  second  stroke  be  given  which 
shall  seem  exactly  as  loud  as  the  first,  we  must 
make  this  second  stroke  slightly  fainter;   we  must 


ences  shrink 
in  memory 


Fig.  37, —  Instrument  for  measuring  variations  in  the  memory 
for  sounds. 


^ 


Memory  and  the  Influence  of  Time      171 

have  the  ball  fall  from  a  point  not  so  high, — 
perhaps  from  the  lower  ball-holder  in  the  figure.  If 
we  make  the  second  sound  of  the  same  actual  intensity 
as  that  which  has  preceded,  in  the  long  run  it  will 
seem  louder  than  the  first  one.  This  means  of  course 
that  the  recalled  sound  is  represented  as  having  less 
strength  than  it  really  pos-sessed.  But  with  certain  while  others 
intensities  of  light,  on  the  other  hand,  the  very  oppo-  ^^p^"^- 
site  effect  is  observed.  The  remembered  light  seems 
brighter  than  it  really  was.  And  also  with  some 
simple  space-forms,  the  objects  seem  to  increase 
rather  than  diminish  as  time  goes  by.  If  a  single 
square  of  moderate  size  be  shown,  and  then,  perhaps, 
twenty  minutes  later,  a  number  of  squares  of  various 
sizes  be  displayed,  in  selecting  the  one  that  seems 
to  be  equal  to  that  presented  earher,  too  large  a 
square  will  usually  be  chosen.  In  looking  back  over 
the  stretch  of  twenty  minutes  the  figure  is  thought  of 
as  larger  than  it  really  was.  So  that  it  is  impossible 
to  say  that  forgetting  is  equivalent  to  a  quantitative 
decrease  in  the  object  forgotten  —  that  time  always 
shrinks  things.  It  may,  on  the  contrary,  make  them 
loom  up  the  larger,  as  things  do  when  seen  dimly 
through  a  mist.  The  fruits  of  the  West  never  seem 
to  the  emigrant  quite  equal  to  those  of  his  New  Eng- 
land farm.  The  golden  age,  the  laiis  temporis  acti^ 
are  but  illustrations  of  this  intellectual  mirage  which 
time  produces.  Some  things  increase  while  others 
decrease;   memory  distorts  everything  for  better  or 


1  Cf.  the  late  Professor  Kennedy's  article  "  On  the  Experimental  Study 
of  Memory,"  Psychological  Review^  Vol.  V,  p.  477,  for  many  details  of 


172  Experimental  Psychology- 

No  necessary  We  cannot  say  that  there  is  any  necessary  con- 
bet"ween  dis-  i^^ction  between  the  indistinctness  and  the  distortion 
tortion  and  which  comcs  ovcr  our  recollections.  We  could  well 
imagine  a  kind  of  mind  in  which  things  would  be 
distorted  in  memory  without  becoming  indistinct,  or 
would  grow  indistinct  without  suffering  further 
change  —  without  seeming  larger  or  smaller,  or 
stronger  or  weaker,  or  better  or  worse.  The  relation 
of  these  different  phenomena  of  memory  might  be 
illustrated  by  the  human  voice.  Recollection  is  like 
a  voice  repeating  something  from  an  ever  increasing 
distance,  but  which,  besides  growing  fainter,  tells  a 
different  story  as  it  passes  into  the  distance.  The 
growing  indistinctness  in  the  voice  would  be  com- 
parable to  the  law  of  forgetfulness  which  Ebbing- 
haus's  experiments  brought  out.    The  change  of  story 

such  experiments.  As  to  the  character  of  the  memory-image  itself,  as 
set  forth  in  my  text,  it  should  be  said  that  there  is  increasing  evidence 
that  when  a  comparison  is  made  between  a  present  impression  and  one 
that  occurred  some  time  before,  there  often  is  no  conscious  picture  of 
this  earlier  occurrence  (cf.  e.g.  Bentley,  "The  Memory  Image  and  its 
Qualitative  Fidelity";  also  Angell  and  Harwood,  "Experiments  on 
the  Discrimination  of  Clangs  for  Different  Intervals  of  Time,"  both 
articles  in  the  American  Journal  of  Psychology y  Vol.  XI,  No.  i,  Octo- 
ber, 1899). 

But  whenever  there  is  a  judgment  with  reference  to  a  preceding  im- 
pression, it  would  seem  that  we  are  conscious  of  the  past  occurrence  in 
some  form  or  other,  if  not  in  kind,  at  least  symbolically  or  "  implicitly." 
I  have,  therefore,  continued  to  speak  of  an  idea  or  representation  of 
the  past  experience  as  involved  in  all  these  acts  of  comparison  or 
discrimination  without,  however,  wishing  to  stand  by  the  memory- 
image  view  in  all  its  rigid  literalness.  The  representation  of  the  past 
occurrence,  whether  it  be  in  the  form  of  a  picture  or  of  something  more 
obscure,  certainly  undergoes  alterations  corresponding  to  what  I  have 
called  indistinctness  and  distortion. 


Memory  and  the  Influence  of  Time      173 

would  stand  for  the  distortion  which  things  suffer  in 
memory.  It  has  been  one  of  the  errors  of  psychology 
to  confuse  these  two  aspects  and  to  explain  all  the 
cases  where  memory  minimizes  things  as  simply  due 
to  the  fainter  voice  with  which  memory  speaks.^ 
But  this  is  entirely  beside  the  mark.  There  is 
no  necessary  connection  between  the  strength  with 
which  words  are  uttered  and  the  amount  of  meaning 
they  convey.  We  can  exaggerate  in  whispers,  or 
belittle  a  thing  in  thundering  tones. 

Why   there   should    be    any    distortion    at    all    is  The 
not  yet  understood.     In  some  cases  the  alteration  ^!!!°^!®^^^ 

-'  difficult  to 

seems  to  be  the  result  of  an  effort  to  make  things  explain, 
more  uniform  in  memory,  —  to  bring  them  nearer  an 
average.  A  very  dim  light,  for  example,  becomes 
brighter  in  memory;  while  a  very  bright  light  be- 
comes dimmer,  as  if  by  gravitation  in  both  cases 
toward  the  mass  or  average  of  our  experiences.^ 
But  often  just  the  opposite  tendency  seems  to  be 
present.  In  my  own  case,  if  two  exceedingly  shrill 
notes  of  a  Galton  whistle,  near  the  upper  hmit  of 
audible  tone,  be  given  with  an  interval  of  time  be- 
tween them,  even  when  the  two  are  of  identical 
pitch,  the  earlier  one  always  seems  to  be  the  higher.^ 
The  extraordinary  experience,  instead  of  being  forced 
toward  what  is  normal,  becomes  even  more  extraor- 


1  For  an  example  of  such  an  error,  cf.  von  Tschisch,  "  Ueber  das 
Gedachtniss  fur  Sinneswahrnehmungen,"  Bericht  u.  d.  Ill  Inter- 
nationalen  Congress  fur  Psychologie,  Munich,  1897,  P«  ^o^. 

^  Cf.  Leuba,  American  Journal  of  Psychology,  Vol.  V,  pp.  382  et  seq. 

8  From  experiments  on  others,  however,  I  am  sure  that  this  is  not 
universally  the  case. 


174  Experimental  Psychology 

dinary  as  it  is  recalled.  Fresh  and  marvellous 
features  are  thus  involuntarily  added  to  what  is 
surprising,  in  order  to  justify  even  to  ourselves  the 
effect  which  we  remember  it  produced  upon  us.  The 
same  tendency  is  seen  in  the  larger  corporate  memory 
of  society,  in  that  every  great  historic  figure,  like 
Luther  or  Napoleon,  soon  becomes  the  centre  of  a 
myth.  But,  again,  the  tendency  may  be  still  more 
irregular,  so  that  it  cannot  be  described  either  as  a 
simple  exaggeration  or  as  a  mere  diminution.  The 
same  remembered  fact  maybe  enlarged  at  one  moment, 
only  to  be  reduced  again  as  it  gets  farther  into  the 
past.  Thus  the  selfsame  sound  or  light  may,  after 
two  seconds,  be  thought  of  as  stronger  than  it  actually 
was,  while  after  two  minutes  it  may  have  fallen  off 
and  be  regarded  as  considerably  weaker  than  the  origi- 
nal fact.^  This,  too,  represents  in  miniature  what  we 
see  on  a  larger  scale  in  history,  where  for  some  brief 
time  after  an  event  its  importance  is  exaggerated, 
only  to  be  undervalued  perhaps  at  a  still  later  day. 

Clarification  But  after  we  have  told  the  whole  damaging  truth 
m  memory,  a^out  memory  and  about  its  tendency  to  distort  and 
obscure  the  facts,  we  must  do  it  justice  as  regards 
its  occasional  power  to  make  the  facts  more  distinct. 
After  an  interval  has  elapsed,  an  experience  may  be 
less  blurred  in  memory  than  it  was  immediately  after 
its  occurrence.  The  clearest  and  most  faithful  view 
of  things  is  here  to  be  had  only  in  the  later  memory- 

1  From  experiments  by  students  in  the  psychological  laboratory  of 
the  University  of  Cahfornia,  an  account  of  which  will  be  published 
soon,  I  hope. 


Memory  and  the  Influence  of  Time      175 

picture.  It  is  said  of  experts  in  tasting  wine  or  tea 
that  their  finest  discriminations  cannot  be  made  until 
the  taste  is  out  of  the  mouth.  And  certainly  any 
one  who  tries  to  observe  his  own  mental  states  will 
find  something  similar  to  this ;  he  can  tell  but  little 
about  them  until  they  are  off  at  arm's  length  —  until 
he  can  see  them  somewhat  in  perspective.  An 
emotion  or  an  act  of  will  can  be  best  scrutinized  only 
in  memory,  so  that  introspection  is  always  more  or 
less  a  matter  of  retrospect.  In  these  cases  memory  » 
seems  to  offer  a  more  stable  and  trustworthy  basis 
of  judgment  than  the  sensible  fact  itself.  So,  ini 
much  of  our  laboratory  work,  it  is  found  that  the 
nicest  distinctions  are  noticed  when  the  two  im- 
pressions which  are  to  be  compared  come  in  suc- 
cession rather  than  at  the  same  time.  Two  weights 
pressing  on  the  skin  simultaneously  cannot  be  dis- 
tinguished until  one  of  them  is  about  one-third 
heavier  than  the  other.  But  if  we  give  them  suc- 
cessively, a  difference  not  a  tenth  as  large  as  this  can 
often  be  perceived.  In  music,  the  untutored  mind 
has  infinitely  greater  readiness  in  comparing  the 
pitch  of  tones  if  one  follows  the  other.  For  this 
reason,  melody  is  easier  of  comprehension  than 
harmony;  few  can  mark  at  once  all  the  different 
notes  in  a  chord ;  we  appreciate  its  general  character 
rather  than  its  individual  constituents.  In  the  case 
of  sight,  it  might  seem  that  the  most  favorable  con- 
ditions for  comparing  things  —  two  colors,  for  exam- 
ple—  would  be  when  both  were  present  at  once. 
But  even  here,  although  the  things  stand  there 
together,  we  actually  compare  them  by  running  the 


176 


Experimental  Psychology 


The  under- 
standing 
plays  a  part 
in  memory. 


eye  back  and  forth,  and  thus  make  the  experience  of 
them  successive.  If  we  put  them  close  together  and 
look  at  them  fixedly,  both  at  once,  the  judgment  is  less 
secure.  Now,  in  all  these  cases  where  comparison  is 
easiest,  we  are  in  some  way  working  by  memory ;  we 
have  to  retain  some  idea  of  the  preceding  impression 
and  compare  it  with  the  one  that  follows.  It  is  evi- 
dent, therefore,  that  what  was  said  about  the  obscur- 
ing effect  of  memory  as  compared  with  the  vividness 
of  the  original  impression,  cannot  be  the  whole  truth. 
The  fact  is  that  experience  is  a  much  less  sensu- 
ous matter  than  we  often  believe ;  the  process  of 
clearing  up  our  experience  —  of  making  it  stand 
vividly  before  us  —  depends  by  no  means  exclusively 
on  the  mere  strength  and  liveliness  of  the  sensa- 
tions of  the  moment,  but  on  subtle  processes  which 
belong  to  the  understanding.  And  these  processes 
work  slowly,  and,  at  any  given  moment,  over  a 
comparatively  limited  field.  We  imagine  that  our 
minds  receive  things  in  the  lump ;  but  even  in  our 
most  rapid  observations  and  with  the  simplest  things, 
the  object  gradually  dawns  upon  us;  it  comes,  now  a 
part  and,  later,  another  part.  If  a  very  simple  form 
be  shown  but  one  brief  moment,  —  -g-J^  of  a  second, 
perhaps,  —  the  light  may  be  strong  enough  to  give 
a  distinct  effect  upon  the  eye;  but  only  a  portion^ of 
the  figure  is  grasped  by  us,  or  we  get  a  suggestion 
of  something  quite  different  from  what  really  ap- 
peared. A  second  exposure  of  the  same  length 
partially  supplements  or  corrects  the  first ;  a  third 
makes  it  still  more  distinct;  until  with  successive 
views  the  figure  at  last  emerges  clear.     In  Fig.  38, 


Memory  and  the  Influence  of  Time      177 


column  O  gives  the  actual  form  of  some  outlines 
exposed  in  this  way,  the  other  columns  (i,  2,  etc.) 
give  the  successive  drawings,  all  by  the  same  observer, 
showing  the  apparent  development  with  the  successive 
exposures.  Now 
each  successive 
view  hardly  adds 
to  the  clearness  of 
the  impression 
upon  the  eye ;  the 
growth  in  the  per- 
ception is  not  a 
matter  of  more 
vivid  sensation. 
The  growing  dis- 
tinctness in  the  ex- 
perience is  rather 
due  to  our  scruti- 
nizing attention  — 
to  our  holding  in 
memory  what  had 
been  gained,  and 
adding  to  this  suc- 
cessively until   we 

finally  have  a  distinct  picture  of  the  figure.  Not  un- 
til we  ourselves  have  built  it  up  at  the  suggestion  of 
the  sensations,  have  we  really  mastered  the  sense- 
impressions  and  made  them  ours.  This  intellectual 
construction  requires  not  only  time,  but  it  requires 
also  freedom  from  distraction ;  and  when  several 
things  are  present  at  once  it  seems  impossible  to  give 
each  that  undivided  attention  which  is  possible  when 


0 

t          t          s          «          5 

N 

^s  h-!  l-i  H    M 

tb 

|]    0    b     5     b 

^ 

-h    y^     ^    ^    ^ 

-»- 

(1_   •*-    -:*-  -"tsr  -*- 

•t 

1_    -t      t      -L    -tl 

p] 

'■/-  /7     q     q     fl 

/^ 

r-    ^    A-    X    /( 

Fig.  38.  —  Examples  of  the  gradual  develop- 
ment (columns  1-5)  of  the  subjective 
image  after  very  short  exposures  of  an 
object  shown  in  column  O. 


The  source 
of  the 
increased 
distinctness. 


178 


Experimental  Psychology 


A  clearer 
retention  pre- 
cedes the 
blurring. 


they  come  to  us  in  succession.  Simultaneous  things, 
consequently,  are  more  difficult  to  compare  because 
each  is  clamoring  for  attention,  and  so  we  cannot 
scrutinize  perfectly  any  one  of  them.  The  sense- 
materials  are  clear  enough,  but  the  intellectual  func- 
tion is  at  a  disadvantage.  Now  this  intellectual  part, 
this  grasp  of  the  thing,  may  continue  to  develop  after 
the  object  is  no  longer  sensibly  present.  In  fact,  in 
some  cases,  the  sensible  presence  of  the  object  really 
hinders  our  understanding  of  it.  After  it  is  gone, 
the  attention  is  more  elastic  and  alert,  the  various 
relations  are  better  seen,  so  that  the  natural  fading  in 
memory  of  the  sensory  impression  may  be  offset,  and 
more  than  offset,  by  this  retrospective  clarifying 
through  the  understanding.  In  historical  studies  it 
has  become  a  truism  that  the  present  is  what  we  know 
least  about ;  it  is  all  confusion,  and  nothing  clears  up 
until  it  can  be  viewed  from  a  distance.  The  same 
holds  true  in  a  large  measure  in"  regard  even  to  the 
inner  experiences  of  our  personal  life.  Thus  it  is 
extremely  significant  that  careful  experiments  on  the 
memory  for  tones,  for  light,  and  the  like,  often  show 
a  steady  improvement  of  memory,  rather  than  a  fall- 
ing off,  during  the  first  five  seconds  (and  sometimes 
longer)  after  an  impression  has  been  received.^  Over 
against  the  general  law  that  memory  allows  the  facts 
rapidly  to  fade,  we  must  therefore  set  up  the  opposing 


1  Such  an  improvement,  for  instance,  is  noticeable  in  several  parts 
of  the  tables  of  Bentley  {American  Journal  of  Psychology^  Vol.  XI, 
p.  42),  of  Angell  and  Harwood  {ibid.^  p.  76),  as  well  as  in  those 
of  Saborski  {Bericht  ii.  d.  Ill  Inter nationalen  Congress  fur  Psychologies 
p.  103)  and  Hirschberg  {ibid.^  p.  107). 


Memory  and  the  Influence  of  Time      179 

principle  that  time  is  frequently  one  of  the  most  im- 
portant factors  in  clarifying  our  experience,  and  at 
first  often  builds  up  more  rapidly  than  the  other  influ- 
ence pulls  down.  So  that  in  all  hasty  or  unstable 
experiences  the  very  maximum  of  clearness  is  reached 
not  while  the  impression  is  upon  us,  but  immediately 
afterward,  in  a  single  early  throb  of  memory. 

But  the  laboratory  work  on  memory  has  made  per-  The  reten- 
haps  its  most  interesting  finds  in  laying  bare  the  dif-  e^t'^se^s^J^^'^' 
-ferent  ways  our  memory  has  of  dealing  with  different  materials. 
materials.     Men  used  to  think  of  memory  as  a  great 
receptacle,  that  was,  like  most  receptacles,  indifferent 
to  the  kind  of  things  put  into  it.     A  "  good  "  mem- 
ory, it  was  thought,  could  retain  anything;  a  poor 
one  allowed  everything  to  escape.     Each  of  us  was 
supposed  to  be  possessed  of  a  certain  grade  of  reten- 
tiveness,  equally  tenacious  or  negligent  (as  the  case 
might  be)  of  all  things  committed  to  it.     But  it  is 
now  known  that  this  is  not  the  fact.     With  all  of  us 
the  power  of  retention  is  very  different  for  different 
things.     And  even  within  the  limits  of  a  single  sense 
in  the  same  person  great  differences  may  be  found. 
Von  Tschisch  not  long  ago  laid  it  down  as  the  result 
of  his  students'  experiments  that  there  is  a  regular 
improvement  of  memory  as  we  pass  from  the  lower 
to  the  higher  senses,  that  we  remember  best  of  all  The  usual 
the  things  we  see  and  hear,  and  poorest  the  objects  If^^^^s  of 

*^  'X'  J  the  senses  as 

of  touch,  while  somewhere  between  the  two   comes  "higher "and 
the  memory  for  facts  obtained  through  the  muscles.^  "lower" 

^  W.  von  Tschisch,  "  Ueber  das  Gedachtniss  fiir  Sinneswahrnehmung- 
en,"  Bericht  u.  d.  Ill  Internationalen  Congress  fur  Psychologie,  p.  95. 


i8o  Experimental   Psychology 

hardly  fits  the       The  scnscs  are  probably  not  related,  however,  in 

acts  ere.       ^j^-^  gjj^pjg  ^^^  orderly  progression ;  and  whether  we 

grade  a  sense  as  higher  or  lower  depends  very  largely 

on  the  particular  features  that  we  are  considering. 

We  are,  as  a  rule,  undoubtedly  more  tenacious  of  the 

size  of  objects  offered  to  the  eyes  than  of  those  which 

touch  our  skin.     But  in  respect  to  the  memory  for 

The  first  may  the  intensities  of  impressions,  there  is  a  reversal  of 

^^^^*'  our   usual  classification  of  high  and  low.      Sight  is 

now  the  poorest  of   all,  hearing  is  only  less  poor, 

while  the   muscular  sense  and  touch  stand  highest 

in  the  scale.^ 

It  is  hardly  probable  that  the  difference  in  the  rate 
of  fading  of  different  aspects  of  our  impressions  is  due 
to  any  peculiar  quality  of  the  impressions  themselves ; 
we  have  no  evidence  as  yet  that  some  features  of  our 
sensations  are  inherently  more  perishable  than  others. 
It  is  rather  because  some  have  become  more  signifi- 
utiiity  as  the  cant  and  have  a  practical  value  and  interest  which 
fecto™^"^"^  others  lack.  Those  features  of  our  impressions  which 
in  the  long  run  stand  for  the  most,  which  have  the 
richest  and  most  permanent  associations  —  these  enter 
into  the  very  weave  of  our  mental  life.  The  actual 
and  absolute  brightness,  for  instance,  of  the  light 
which  comes  from  objects  is  decidedly  less  impor- 
tant for  dealing  with  them  than  are  their  shapes 
and  sizes.  The  absolute  brightness  changes  con- 
stantly with  the  weather  or  the  time  of  day,  but  not 
so  the  form.  And  similarly  the  absolute  loudness  of 
sounds,  while  important  for  judging  distance,  is  of 

1  From  the  results  of  experiments  by  my  students,  referred  to  a  few 
pages  before. 


Memory  and  the  Influence  of  Time      i8i 

far  less  general  importance  for  telling  whether  things 
are  harmful,  and  for  purposes  of  communication,  than 
are  the  peculiar  qualities  and  pitches  of  sounds.  For 
this  reason  our  power  to  recognize  the  j)itch  of  a 
sound  given  some  moments  before,  poor  though  it 
may  be,  is  usually  better  than  our  ability  to  recognize 
the  particular  intensity  or  loudness  of  the  sound.  On 
the  other  hand,  the  weights  and  pressures  of  objects 
are  often  permanently  characteristic  of  them,  and  are 
important  for  our  recognition  and  practical  treatment 
of  them.  The  superiority  of  our  faculty  to  recognize 
intensities  of  pressure  and  muscular  strain  as  compared 
with  our  recollection  of  the  intensities  of  sights  and 
sounds  is  consequently  a  matter  of  biological  utility. 

The  importance  which  certain  features  of  experi-  Effect  of 
ence  shall  have  is  not,  however,  a  fixed  matter  and  ^'^^'"^'^  <^o^- 

'  '  ditions. 

aUke  in  all  persons.  In  many  cases  —  in  the  blind, 
and  in  the  deaf,  for  example  —  the  relative  values 
of  different  kinds  of  impressions  may  be  unusual. 
When  a  person  must  depend  largely  upon  touch, 
he  may  have  a  memory  for  gradations  and  niceties 
in  this  field  that  is  astonishing.  If  there  is  any  truth 
in  the  common  behef  that  the  blind  can  at  times  dis- 
tinguish colors  by  feeling,  it  must  be  that  different 
dyes  give  characteristic  impressions  of  touch  —  gritty 
or  smooth  or  cold  —  which  are  noticed  and  remem- 
bered and  classified  and  associated  with  our  color 
names,  but  without  any  true  perception  of  the  colors 
themselves.  But  while  the  memories  of  the  blind  are 
richly  furnished  with  tactual  ideas,  sounds  also  have 
a  prominent  place  with  them.  In  recalling  persons 
their  thought  circles  about  the  voice,  while  with  us 


1 82  Experimental  Psychology- 

such  recollections  group  about  the  appearance  of  the 
face.  Their  dreams,  too  (which  are  a  kind  of  mem- 
ory), are  largely  in  terms  of  sound,  often  running, 
even  in  persons  not  especially  interested  in  literary 
matters,  into  the  form  of  verse.^  One  of  the  most 
interesting  things  in  Raehlmann's  account  of  the 
relief  of  Christine  Deutschmann  from  congenital 
blindness  is  the  pleasure  the  woman  took  in  the 
change  that  came  over  her  dreams ;  they  became 
visual  pictures  where  she  had  before  of  course  seen 
nothing.2  The  deaf,  on  the  other  hand,  when  dream- 
ing or  when  delirious,  imagine  and  at  times  actually 
produce  the  movements  of  the  manual  sign  language 
where  we  should  hear  or  use  the  voice.  Likewise 
in  the  animal  world,  memory  must  take  on  an  entirely 
different  tone,  and  the  relative  tenacity  for  various 

1  Cf.  the  interesting  account  of  the  dreams  of  the  blind,  by  Friedrich 
Hitschmann  (himself  blind),  "Ueber  das  Traumleben  des  Blinden," 
Zeitschrift  fur  Psychologie  und  Physiologie  der  Sinnesorganej  Vol.  VIII 
(1894),  p.  387. 

To  illustrate  the  rhythm  feature,  he  gives  from  the  dream  of  an 
unliterary  friend :  — 

"  Es  trippelt  Freund  Hein 
In  der  Nacht 
In  der  Nacht 

Ganz  sacht." 

The  dreamer  then  murmured  to  himself  (still  asleep)  :  — 

"  Zwolf  Worte,  zw6lf  Tote,  es  stimmt." 

He  says  that  he  himself  often  hears  whole  lectures  in  his  dreams. 
The  touch  element,  according  to  him,  is  almost  if  not  quite  absent. 
For  instance,  he  dreams  of  a  fire,  but  feels  no  glow  from  it;  it  seems 
to  be  more  a  matter  of  words, 

2  Raehlmann,  "  Physiologisch-psychologische  Studien,"  etc.,  Zeit- 
schrift fur  Psychologie  und  Physiologie  der  Sinnesorgane,  Vol.  II,  p.  53. 


in  normal 
persons. 


Memory  and  the  Influence  of  Time      183 

impressions  is  then  at  times  completely  reversed. 
The  conduct  of  dogs,  for  example,  shows  that  their 
memory  must  be  one  vast  array  of  odorous  detail. 
Sight,  instead  of  playing  the  chief  role,  as  with  us, 
is  with  them  subordinate,  a  mere  rudimentary  sug- 
gester  of  possible  and  coming  scents.  When  they 
must  depend  solely  upon  the  sight  of  things,  they 
behave  somewhat  as  we  do  in  the  dark.^ 

And  even  in  what  seem  to  be  normal  persons,  great  variations 
variations  exist  in  the  relative  importance  of  sight  and 
hearing  in  furnishing  the  means  of  recognition  or 
recall.  I  have  a  friend  who  cannot  recall  or  recognize 
a  single  simple  melody,  although  his  hearing  has 
apparently  the  normal  acuteness.  The  recollection 
for  such  things  in  his  case  is  blank.  He  was  confi- 
dent that  he  could  recognize  Dixie  (he  was  a  South- 
erner), but  we  soon  found  that  the  rhythm  alone  was 
appreciated,  and  if  other  notes  were  thrown  into  the 
same  cadence  it  seemed  to  him  the  familiar  melody. 
Another  friend  has  a  vague  sense  of  recognition  when 
certain  music  is  played  but  cannot  "place"  the  com- 

1  This  subordination  of  sight  in  the  dog  was  impressed  upon  me 
afresh  while  watching  recently  a  fine  hunting  dog  try  to  trace  his  way 
under  circumstances  where  smell  could  not  give  the  usual  clew.  An 
electric  car  upon  which  his  master  was  riding  slowed  up  and  the  dog 
jumped  off,  while  the  car  with  the  man  aboard  passed  on.  The  dog, 
of  course,  found  at  once  that  his  master  was  not  with  him.  But  instead 
of  following  the  car,  —  which  was  on  a  clear  street  and  not  going  faster 
than  he  could  run,  while  the  dog's  owner  was  in  plain  view  on  the  out- 
side trying  to  get  the  dog's  notice,  — the  dog  set  up  a  wild  search  for 
a  ground  scent,  running  up  and  down  the  track,  and  to  and  fro  on  a 
cross-street  near  by.  This  blind  hunt  lasted  some  time,  until  his 
master,  who  had  alighted  perhaps  two  hundred  yards  farther  on, 
finally  attracted  the  dog's  attention  by  his  call. 


value  of  the 
results. 


184  Experimental  Psychology 

position  unless  it  suggests  words ;  through  them  alone 
the  piece  is  fully  recognized.  Some  persons  can  re- 
member much  better  what  they  hear;  others  have 
more  definite  recollection  of  things  they  see.  I  know 
a  lady  who,  after  a  single  glance  at  an  engraving  never 
seen  before,  can  answer  questions  as  to  minute  details 
of  the  drawing  that  were  not  noticed  in  the  short  in- 
terval when  the  picture  was  shown.  The  answers 
are  given  by  mentally  recalling  the  picture  and  sub- 
mitting it  to  an  examination  as  if  it  were  sensibly  there. 
What  the  explanation  of  this  difference  of  memory 
type  is  we  do  not  know. 
Practical  Our  modem  psychology  has  thus  done  much  to  un- 

fold the  variations  and  oddities  of  memory.  And  such 
discoveries  are  not  merely  curious,  but  are  also  of 
practical  importance,  especially  in  the  conduct  of  the 
schools.  How  many  children  have  been  accounted 
stupid  simply  because  no  one  appreciated  the  peculiar 
difficulties  under  which  they  worked !  They  were 
expected  to  retain  materials  that  had  no  affinity  for 
their  particular  constitution.  And  their  failure  was 
counted  a  moral  wrong,  laid  at  the  door  of  the  will  or 
of  their  inattention,  when  in  reality  the  difficulty  was 
not  there  at  all.  The  present  interest  in  child-study 
in  the  schools  has  already  prepared  the  way  for  a 
more  intelHgent  and  sympathetic  treatment  of  these 
personal  differences.  To  a  teacher  interested  in  psy- 
chology, not  as  a  bookish  doctrine,  but  as  a  thing  of 
flesh  and  blood,  a  child  who  cannot  learn  to  spell 
should  be  regarded  as  a  rare  and  inviting  individual 
who  may  not  be  dismissed  until  he  has  yielded  up  the 
secret  of  his  defective  memory. 


CHAPTER  X 
TEMPORAL    SIGNS    AND    THE    RANK    OF    MEMORY 

So  far  we  have  confined  our  attention  to  the  vivid-  How  do  we 
ness  and  fideUty  of  our  recollections  and  to  the  differ-  fh^^^^r^f 
ence  in  these  respects  in  different  minds,  and  in  the  impressions? 
same  minds  when  dealing  with  different  materials. 
But  there  is  another  important  feature  which  we  have 
now  to  consider,  namely  the  matter  of  temporal  signs. 
In  the  chapter  on  the  consciousness  of  space  the 
question  of  local  signs  was  considered  —  how  we  are 
able  to  distinguish  the  place  in  the  outer  world  from 
which  various  messages  come,  and  refer  each  to  its 
appropriate  locality.  There  is  a  similar  problem  in 
regard  to  memory.  How  are  we  able  to  refer  our 
countless  memories  each  to  its  proper  region  of  the 
past  ?  Each  idea  of  the  past  is,  while  we  remember 
it,  a  present  mental  act,  and  yet  we  somehow  distin- 
guish the  various  items,  and  with  perfect  security 
say  that  some  are  of  recent  events  while  others 
belong  to  the  early  years  of  childhood.  What  is 
there  in  these  various  memories  that  suggests  to  us 
the  time-order  in  which  we  should  arrange  them; 
what,  in  other  words,  are  their  temporal  signs } 

It  would  be  gratifying  to  our  laboratory  and  me-  is  it  accord- 
chanical-science  instinct  if  we  could  truthfully  assert  difti^nctnes^s  ? 
that  it  is  all  a  matter  of  distinctness  in  the  various 

185 


i86 


Experimental  Psychology 


But  the 
vague  is 
often  felt  to 
be  recent. 


No  one 
formula  suf- 
fices. 


pictures,  the  more  sharply  outlined  memories  being 
adjudged  to  belong  to  more  recent  events,  while  the 
vaguer  are  felt  to  be  of  an  earlier  date.  Distinctness 
of  course  is  not  the  same  as  simple  intensity.  Very 
weak  things  —  a  whisper  close  to  the  ear — may  be 
very  distinct,  while  much  louder  tones  coming  from 
the  next  room  may  be  obscure.  The  memories  that 
are  most  definite,  that  have  the  most  nicely  marked 
details,  would,  according  to  this  view,  seem  the  more 
recent,  while  the  obscurer  ones  would  be  referred  to 
a  remoter  past. 

Now  while  many  of  the  facts  would  undoubtedly 
be  consonant  with  this  view,  yet  as  a  whole  they  will 
not  sanction  so  simple  a  rule.  The  recollections 
that  we  know  are  but  of  yesterday  are  often  more 
vague  than  others  that  we  consciously  refer  to  an 
earlier  date.  Most  of  us  could  give  a  more  coherent 
account  of  last  summer's  outing  than  of  what  occurred 
at  the  last  dinner  we  attended,  or  could  recall  more 
distinctly  our  reading  of  Gulliver  than  of  yesterday's 
newspaper.  And  yet  we  make  no  confusion  of  rela- 
tive dates.  The  experiences  recalled  more  distinctly 
are  nevertheless  felt  to  belong  to  an  earlier  time. 
Distinctness  consequently  does  not  decide  the  order 
of  memories. 

The  basis  of  our  decision  here  is  exceedingly  subtle 
and  complex.  It  is  like  our  judgment  of  the  relative 
distances  of  objects  from  us  :  no  one  formula  will  fit 
all  the  facts.  In  determining  relative  distances  from 
us  in  space,  we  are  undoubtedly  influenced  by  the 
intensity  and  distinctness  and  size  of  the  objects,  and 
by  atmospheric  and  line  perspective;  and  now  one 


Temporal  Signs  187 

and  now  another  of  these  factors  has  the  upper  hand. 
And  moreover  the  basis  upon  which  we  decide 
the  relative  distances  of  things  in  the  foreground 
where  binocular  vision  is  effective,  with  its  inequality 
in  the  pictures  given  by  the  two  eyes,  is  entirely 
different  from  that  in  regard  to  objects  far  away. 
So,  in  ordering  our  memories,  there  are  many  tem- 
poral signs,  and  those  that  govern  us  in  regard  to 
recent  events  are  not  the  same  as  for  occurrences 
more  remote.  In  memory  there  is  a  certain  fore-  The  temporal 
ground  where  things  stand  out  from  each  other  ^°^^&^°^^^- 
in  a  kind  of  plastic  relief,  as  in  some  temporal 
stereoscope,  and  we  seem  actually  to  perceive  the 
time  between  them.  The  order  in  which  we  hold 
these  recent  events  probably  depends  upon  obscure 
gradations  of  emotion,  or  perhaps  even  of  sensa- 
tions which  accompany  the  memory-images  and  sug- 
gest to  us  the  time  to  which  they  belong.  The  dis- 
tinctness of  our  memories  may,  indeed,  be  an  impor- 
tant factor,  although  by  no  means  all-important. 

But,  after  all,  and  especially  when  we  try  to  interre-  More  remote 
late  events  lying  in  the  more  distant  past,  our  main  ^^p^"^^^^^- 
dependence  is  upon  our  knowledge  of  how  things 
ou£-/it  to  go  together,  rather  than  upon  simple  sensa- 
tions or  emotions  or  upon  the  element  of  distinctness. 
We  learn  some  of  the  more  elementary  laws  of  nature 
and,  guided  by  them,  set  up  certain  mnemonic  land- 
marks ;  and  then,  with  these,  we  connect  our  subordi- 
nate memories,  knowing,  as  we  do,  what  their  causal  re- 
lation was,  and  what  order  they  must  have  had.  The 
psychology  of  space  will  again  furnish  a  useful  par- 
allel.    A  mountain  is  seen  as  lying  beyond  the  distant 


logical  mo- 
tives, 


1 88  Experimental  Psychology 

bay,  not  because  the  impression  of  bay  and  moun- 
tain are  each  accompanied  by  some  immediate 
local  sign  that  tells  what  their  relative  distance  is, 
but  because  it  would  violate  all  our  knowledge 
of  nature  to  suppose  that  the  mountain  was  really 
between  us  and  the  bay,  and  yet  the  bay  visible. 
We  should  have  to  suppose  that  the  mountain 
was  transparent,  or  was  floating  unsupported  in  the 
air.  Our  appreciation  of  the  orderliness  of  nature, 
our  conviction  of  causal  regularity,  here  decides 
Influence  of  the  day.  So  in  memory,  the  order  of  events  is  in 
most  cases  not  decided  by  some  different  sensational 
or  emotional  sign  attached  to  the  various  recollections, 
but  by  our  conviction,  based  upon  our  knowledge  of 
cause  and  effect,  that  any  other  arrangement  would 
be  an  intellectual  absurdity.  I  feel  that  a  certain 
ocean  voyage  precedes  a  visit,  say,  to  the  city  of 
Guatemala,  because  I  know  that,  putting  my  life 
together  as  a  whole,  things  will  not  fit  one  another  in 
any  other  way.  The  circumstances  were  such  that 
the  voyage  was,  as  the  world  goes,  a  precondition  of 
my  seeing  the  city  at  all.  In  the  same  way  we  refer 
our  memories  of  childhood  to  a  remoter  past  than 
those  of  youth,  not  by  reason  of  their  greater  obscu- 
rity nor  the  different  emotional  tone  which  is  un- 
doubtedly connected  with  each,  but  because  it  is  the 
natural  order  of  life,  of  which  we  have  become 
convinced.  A  feeling  for  the  inteUigibility  of  the 
memory-system  as  a  whole  —  a  sense  of  the  impossi- 
bility of  understanding  our  past  unless  its  order  be 
thus  and  so  —  largely  influences  us.  A  subtle  intel- 
lectual fondness  for  certain  arrangements  rather  than 


Temporal  Signs  189 

others,  due  in  part  at  least  to  our  experience  and 
training,  is  of  more  influence  here  than  any  purely 
quantitative  guide.  Since  the  memory-process  is  thus 
so  interwoven  with  the  judgment  and  the  understand- 
ing (unreflective  and  unconscious  though  their  opera- 
tion may  be),  not  to  speak  of  its  connection  with 
the  senses  and  the  emotions,  we  must  give  up  the 
belief  that  memory  is  a  distinct  and  separate  faculty. 
Our  higher  intellectual  functions  are  part  and  parcel 
of  it. 

But  this  seems  to  conflict  with  the  abundant  evi-  How  can 
dence  that  memory  comes  very  early  in  the  mental  ^^^^_^  ^® 
development.     Emerson  appears  to  be  not  far  from  mental? 
the  most  modern  teachings  of  Genetic  Psychology 
when  he  says  that  memory  is  the  fundamental  faculty 
without  which  none  other  could  exist ;  that  it  is  the 
matrix  or  womb  of  all  our  higher  powers.^     But  from 
the  sketch  just  given  of   the  various  elements   that 
contribute  to  its  perfection,  memory  would  seem  to  be 
too  difficult  and  complex  a  thing  to  appear  at  the  very 
dawn  of  life.     So  that  we  are  now  forced  to  ask  what 
is  the  true  rank  of  memory;  what  is  its  place  and 
function  in  our  growth  .? 

We  are  accustomed   to  use  the  word  "memory"   it  must  be 
in  quite  different  senses,  and  our  answer  to  the  ques-  fj^ett  ani-^^ 
tion  will  depend  upon  the  meaning  which  we  choose,  mais. 
If  we  mean  by  it  a  mere  persistence  of   influences 
from  the  past,  memory  is   certainly  the  basis  of  all 
development    whatever.      Instead   of    being   a   late 
comer,  there  can  be  no  growth  without  it.     Unless 

1  Emerson,  Natural  History  of  Intellect,  Boston,  1894,  p.  63. 


190 


Experimental  Psychology 


Mere  persist- 
ence vs. 
conscious 
recall. 


the  creature  could  retain  the  marks  of  what  it  had 
endured,  there  would  be  no  progress ;  it  could  make 
no  gains,  it  would  at  each  moment  return  to  an  abso- 
lute beginning.  What  we  call  experience,  from  which 
we  are  inclined  to  explain  so  many  of  our  mental 
acts,  is  itself  impossible  unless  there  be  retention. 
The  bare  impressions  of  the  moment,  stripped  of  all 
associations  and  suggestions  springing  from  the  past, 
could  of  course  have  no  meaning.  The  feeling  of 
the  passage  of  time,  the  feeling  that  there  are  real 
things  outside  us,  not  to  speak  of  our  higher  percep- 
tion of  law  and  order,  are  consequently  dependent 
upon  our  power  to  keep  at  least  something  of  what 
we  have  passed  through.  Memory  in  this  sense  may 
be  traced  down,  almost,  if  not  fully,  to  the  bottom  of 
the  animal  scale. 

But  we  must  distinguish  between  the  mere  persist- 
ence of  influences  from  the  past,  and  a  conscious  re- 
call of  the  past.  Memory,  in  the  higher  sense,  is  an 
exceedingly  complicated  act.  In  order  to  remember, 
in  this  strict  sense,  not  only  must  we  have  had  the  past 
occurrence  continue  within  us,  but  it  must  actually 
influence  us  to  the  point  of  arousing  a  present  idea 
and  of  making  us  recognize  this  as  standing  for  a  past 
event.  Imagery  alone  is  undoubtedly  a  compara- 
tively high  achievement;  but  memory  goes  even 
farther,  and  makes  the  present  images  stand  for  a 
reality  beyond  them,  which  is  past.^ 


1 1  am,  of  course,  referring  here  only  to  the  clearest  and  most 
explicit  forms  of  recollection,  which  are  of  a  very  high  order  of  devel- 
opment. That  there  are  lower  forms  which  are  (relatively  and,  per- 
haps, absolutely)  imageless,  I  have  no  doubt,    Cf.  note,  p.  172, 


Temporal  Signs  191 

Now  there  is  no  good  reason  to  believe  that  the  Memory  in 
lower  forms  of  life  ever  consciously  picture  the  past  seng^^co^eY 
and   recognize   it  as   such,  —  ever  recall   preceding  late, 
events  and  know  them  as  belonging  to  an  earlier  date. 
Reminiscence  implies  a  withdrawal  from  the  storm 
and  stress  of  life,  a  subordination  of  the  present,  and 
a  comparatively  unpractical  interest   in  things  —  an 
interest  that  is  the  immediate  precursor  of  art.     For 
this  reason  Memory  is   indeed   the   Mother  of  the 
Muses. 

But  in  the  mind  of  animals  and  very  young  chil-  Animals* 
dren  there  is  hardly  anythinsr  approaching  this  free  J"^.^""^  ^"^. 

J         J  o       rr  o  their  recogni- 

reminiscence.  Perhaps  the  best  illustration  of  what  tionofob- 
their  state  may  be  is  found  in  certain  aspects  of  our  ^^^^* 
dream-consciousness.  In  spite  of  its  fantastic  char- 
acter the  dream-state  is  often  exceedingly  matter- 
of-fact  and  at  the  opposite  pole  from  that  of  art. 
Imaginative  though  dreams  may  be,  we  are  perhaps, 
while  in  them,  usually  in  a  practical  frame  of  mind, 
absorbed  in  the  affair  of  the  moment,  and  without 
any  desire  to  play  with  our  ideas  or  impressions, 
or  to  connect  them  into  a  system  of  the  past.  And 
yet  the  past  is  of  course  the  source  from  which 
the  material  of  our  dreams  for  the  most  part  has 
actually  come ;  but  we  fail  to  recognize  it  or  re- 
fer it  to  its  date.  In  this  respect  we  all  have  some- 
thing like  a  direct  experience  of  the  animal's  plane 
of  thought,  so  far  as  its  mere  attitude  toward  the  past 
is  concerned.  Animals  and  babes  make  use  of  the 
past  but  without  free  recall.  Their  dreams,  there- 
fore, are  no  evidence  of  recollection  in  the  higher 
sense.     And  moreover  the  recognition  of  places  and 


192  Experimental  Psychology- 

persons  which  dogs  or  horses  display  seems  never 
to  go  so  far  as  to  excite  an  independent  interest 
in  recalling  and  organizing  the  suggestions  which 
the  object  arouses;  the  mere  feeling  of  familiarity 
itself  satisfies  them,  and  no  questions  are  asked  as 
to  its  cause  or  justification.  It  will  not  do,  however, 
to  be  too  positive  in  describing  the  mental  life  of 
animals,  and  one  should  always  preserve  a  wholesome 
doubt  as  to  the  finality  of  his  assertions  here. 

Memory  If  SO  large  a  company  of  minds  as  the  greater  part 

Tdentu^^^^"^^  of  the  entire  animal  kingdom  and  the  younger  mem- 
bers of  the  human  family  seem  only  to  be  influenced 
by  the  past,  and  not  to  be  reminiscent,  we  can  hardly 
say  that  memory  in  the  higher  sense  is  really  a  funda- 
mental process.  But  while  many  persons  would  per- 
haps accept  the  notion  that  memory  might  be  absent 
in  the  lower  forms  of  life  and  consequently  should 
not  be  regarded  as  fundamental  in  the  sense  in  which 
the  evolutionist  would  understand  the  word,  yet  they 
would  hold  that  it  is  fundamental  for  us  now  as  moral 
beings,  since  it  is  the  basis  of  personal  identity  and 
continuity.  Is  not  memory  the  only  thing  that  keeps 
our  consciousness  from  breaking  up  into  numberless 
fragments  ;  the  only  thing  that  unites  our  scattered 
experiences  into  one  continuous  life  ?  And  if  memory 
ever  really  loses  its  entire  possessions,  as  it  seems  to 
do,  in  a  large  measure,  in  old  age,  and  as  many  suppose 
it  does,  entirely,  at  death,  would  not  this  mean  essen- 
tially the  end  of  the  particular  person  ?  Any  renewal 
of  experience  thereafter  would  be,  to  all  intents  and 
purposes,  the  development  of  a  new  person,  and  not 


Temporal  Signs  193 

in  any  real  sense  a  continuation  of  the  old.  The 
question  of  the  place  of  memory,  and  of  our  depen- 
dence on  the  actual  contents  which  memory  retains, 
is  therefore  a  weighty  one  for  our  moral  future. 

To  a  large  extent  the  answer  is  prepared  in  what  The  sources 
has  already  been  said.  I  have  tried  to  show  that  contlnuUy^ 
there  is  a  development  and  growth  in  the  lower  forms 
of  life  which  cannot  be  ascribed  to  a  conscious  repro- 
duction of  the  past.  In  animals  and  young  children 
their  past  is  at  work  in  them ;  their  personal  experi- 
ence continues  to  affect  them,  even  though  not  con- 
sciously recalled.  To  retain  the  advantage  of  what 
we  have  experienced  and  to  keep  it  as  a  part  of  our 
personal  life,  it  is  not  necessary  to  have  it  before  us 
in  reminiscence.  Benefits  forgot  are  not  the  same 
as  benefits  annulled.  We  need  not  remember  our 
school-days  in  order  to  continue  to  profit  by  what 
they  gave  us.  The  first  two  years  of  childhood  are 
as  much  a  part  of  us  in  their  lasting  moral  worth  as 
any  other  years  of  our  life.  It  seems  a  more  vital 
matter  that  an  individual  or  a  nation  should  have  a 
good  history  than  that  it  should  reviezv  its  history. 
I  cannot  therefore  attribute  to  conscious  recall  the 
all-important  place  that  some  would  give  it.  A 
distinct  and  continuous  life  may  have  its  growth  and 
moral  training  without  our  being  able  to  look  back 
and  examine  the  sources  from  which  that  life  has 
flowed.  Memory,  then,  is  not  the  only  thing  that 
keeps  consciousness  from  breaking  into  atoms,  or 
that  binds  our  life  into  a  continuous  whole. 

But  while  conscious  reminiscence  is  not  absolutely 
indispensable  for  personal  continuity,  and  while  we 


194  Experimental  Psychology 

Theinflu-       may   suppose   that  interruptions    of    memory   need 
Mon^su^on  ^^^    interrupt    our    intellectual    and    moral   growth, 
conduct.         is  it  not  true  that  our  conscious  memories  have  an 
important  influence  upon  conduct,  and  that  to  a  large 
extent  our  moral  stability  would  be  upset  by  a  loss  or 
change  of  recollections  ?     I  think  we  must  admit  that 
to  some   extent  this   is  true.     The  actual   contents 
which  memory  presents  influence  our  acts.     We  do 
good  to  those  who  have  done  good  to  us.     We  are 
all  more  or  less  influenced  by  the  thought  of  con- 
sequences that  have  come  from  former  deeds.     We 
hesitate   to    do    things    that    are   inconsistent   with 
pledges  given.     Remembered  precedent  is  thus  an 
important  factor  in  private  life  as  well  as  in  law  and 
Their  impor-  politics.      And  yet,  admitting  the  force   of  all  this, 
tance  is  often  ^^  ^^.^  ^^  ^^  attribute  much  more  influence  to  our 

overesti-  ^ 

mated.  memories  as  guides  of  conduct  than  they  really  have. 

They  are  relatively  surface  things,  and  less  effectual 
than  they  seem.  Beneath  all  is  the  great  under- 
current of  life  carrying  the  memories  themselves 
along,  rather  than  guided  by  them.  For  instead  of 
our  being  the  slaves  of  what  we  recall,  our  character 
itself  largely  determines  what  shall  be  remembered 
and  what  we  shall  forget,  and,  most  important  of  all, 
determines'the  weight  or  force  which  the  past  event 
The  scale  of  shall  possess.  For  there  is  no  fixed  and  inherent 
what^counts  f^^ce  which  a  recollection  exerts  upon  us  irrespective 
of  our  deeper  constitution.  We  ourselves,  according 
to  our  aflfinities,  lay  stress  on  this  or  that  particular 
item  of  the  past  and  give  it  value  and  importance. 
In  regard  to  precedents,  there  are  really  such  for  every- 
thing and  anything  you  please,  and  we  pick  and  choose 


Temporal  Signs  195 

the  one  that  falls  in  with  our  dominant  interests; 
so  that  the  great  interests  of  the  individual  or  of  the 
community  determine  what  shall  be  the  controlling 
precedent,  or  with  what  part  of  our  history  we  shall 
act  consistently.  For  a  long  time,  as  a  people,  we 
remembered  our  own  struggle  for  self-government 
and  the  words  of  the  Declaration  of  Independence, 
and  it  seemed  that  these  memories  were  guiding  our 
conduct  toward  our  neighbors;  but  since  the  naval 
fight  at  Manila,  what  an  altered  weight  these  memories 
have  received !  It  is  not  so  much,  then,  what  we 
remember,  as  it  is  the  weight  that  we  give  to  our 
recollections.  The  scale  of  values,  after  all,  is  what 
counts  ;  and  while  memory  to  some  extent  determines 
what  the  scale  shall  be,  yet  to  an  incomparably  larger 
extent  it  is  fixed  by  inner  dispositions  and  habits  that 
need  not  be  remembered  at  all,  in  that  they  have 
become  bone  of  our  bone  and  flesh  of  our  flesh. 

I  think  that  from  still  another  side  memory  may  be  in  due  time 
seen  to  be  less  essential  to  moral  development  and  ^^^ord^^^ 
personal  continuity  than  we  are  usually  inclined  to  nated. 
admit.     For  with  the  growth  of  insight  into  the  laws 
of  the  world,  memory   is   being    given  a  more  and 
more  subordinate  place.     We  are  indeed  already  in 
possession  of  a  power  which  in  many  respects  does 
the  task  of   memory  more  effectually  than  memory 
itself.     I   have  already  spoken  of  the  role  that  our 
knowledge  of  the  order  of  nature  plays  in  deciding 
the  sequence  and  connection  of  our  memories.     But 
it  really  does  more  than   that;  it  supplements   and 
corrects   memory   in   various   ways.     Men    used   to 
know  only  so  much  of  the  past  as  they  could  per- 


196 


Experimental  Psychology 


Reconstruc- 
tion of  the 
past  by  in- 
sight. 


Even  in  the 
plain  man, 
reason  lords 
it  over 
memory. 


sonally  remember,  or  so  much  as  was  handed  down 
by  tradition  —  tradition  being  the  corporate  memory 
of  society.  But  we  have  now  gone  beyond  that 
point,  and  are  able  to  know  whether  the  tradition 
itself  is  right  or  wrong,  and  to  see  farther  than  its 
utmost  reach.  Science,  working  by  insight  into  the 
laws  of  things,  successfully  reproduces  the  past  in  a 
more  accurate  and  larger  way  than  recollection.  For 
example,  by  means  of  geology,  we  can  recover  periods 
of  time  long  before  man's  life  upon  the  earth. 

There  are  thus  two  ways  of  reconstructing  the  past 
which  are  psychologically  and  in  their  practical  results 
quite  distinct:  by  memory,  as  a  kind  of  mechanical 
association  in  which  there  is  little  need  of  understand- 
ing the  why  and  wherefore  of  events,  — evening  knowl- 
edge, cognitio  vespertina^  as  it  has  been  called ;  and 
in  contrast  with  this,  there  is  the  reconstruction  by 
insight  into  the  necessary  nature  of  things,  —  morning 
knowledge,  cognitio  matutina^  when  passive  memory 
is  brushed  aside,  and  fresh  and  vigorous  intellect 
comes  into  play.  As  insight  grows,  memory  becomes 
more  and  more  subordinate ;  the  present  facts  them- 
selves reveal  what  must  have  been  their  history :  we 
can  thus  see  what  they  imply,  much  as  an  expert  can 
glance  at  a  thigh-bone,  and  tell  what  feet  and  jaws 
the  beast  possessed.  ^^ 

It  may  seem  fanciful  perhaps  to  speak  of  the 
time  when  this  shall  be  a  universal  art;  when  the 
world  shall  be  so  transparent  that  we  may  forget  all 
things  without  loss,  because  we  can  at  will  reproduce 
them,  having  become  possessed  of  the  secret  formula 
of  their  construction.     But  that  is  at  least  the  "  limit " 


Temporal  Signs  197 

toward  which  we  are  moving;  and  indeed  we  are 
already  some  distance  on  the  way.  The  grasp  of  the 
facts  by  understanding  rather  than  by  memory  is  not 
confined  to  the  savant ;  the  plain  man  uses  it  in  his 
own  domain.  Whatever  our  theoretical  reverence  for 
memory  may  be,  none  of  us  now  pays  great  practical 
respect  to  it ;  what  it  tells,  we  accept  half-heartedly 
and  with  suspicion,  never  fully  believing  it  unless 
reason  approves.  I  seem  to  recall  that  the  facts  were 
thus  and  so,  and  yet  reject  this  and  believe  the  op- 
posite because  from  certain  present  evidences  I  know 
that  the  event  must  have  been  otherwise.  In  this  way, 
reason  lords  it  over  memory,  modifying  and  rejecting 
her  work  without  reserve. 

And  yet  it  will  not  do  to  make  the  contrast  too  Memory  is  a 
sharp,  nor  to  suppose  that  memory  can  be  entirely  *^^"sition 
laid  aside.  For  with  us  at  present,  memory  is  the 
necessary  means  of  rising  superior  to  memory.  Our 
insight  is  not  as  yet  sufficient  to  enable  us  to  detect 
in  our  immediate  and  present  perceptions  a  wide 
range  of  unperceived  facts.  So  that  we  must  depend 
upon  memory  to  furnish  the  larger  store  of  experi- 
ence with  which  reason  works.  It  is  consequently 
through  our  power  of  recollection  that  we  attain  that 
preliminary  familiarity  with  nature  and  its  laws  by 
which  we  are  able  later  to  turn  upon  memory,  correct 
it,  and  even  shake  ourselves  free  from  its  dominion. 
The  course  of  development,  therefore,  it  seems  prob- 
able, is  from  an  initial  state,  in  animals  and  children, 
which  is  without  consciousness  of  the  past,  through  a 
period  of  memory  and  recollection,  and  then  onward 
toward  a  condition  of  even  more  perfect  consciousness 


198  Experimental  Psychology 

of  the  past  than  memory  gives ;  but  by  insight  and 
not  by  mechanical  retention.  Memory  thus  stands 
between  these  extremes  as  a  happy  transition  expe- 
dient, an  easy  makeshift,  mercifully  given  us  during 
the  days  of  our  ignorance,  so  that  we  may  have  the 
world  before  us  without  the  need  of  understanding  it. 
Some  such  thought  seems  intended  by  Beatrice  when 
she  says  to  Dante  ^  that  the  angels  have  no  need  of 
memory,  because  there  is  no  interruption  of  their 
vision  ;  they  see  all  things  constantly  reflected  in  the 
divine  countenance. 

1  Paradise^  Canto  XXIX,  11.  80,  81. 


..*^' 


CHAPTER  XI 
IMITATION   AND   SUGGESTION 

It  is  a  comparatively  recent  insight  that  imitation  The  worth  of 
and  suggestion  are  pervasive  and  significant   facts.  o^JlTre^entiy 
For  a  long  time  they  were  thought  to  be  of  minor  im-  recognized. 
portance,  coming  occasionally  and  having  prominence 
only  in  persons  of  little  original   power.     Imitation 
was  counted  a  mark  of  immaturity,  children  and  child- 
like creatures  generally  being  almost  the  sole  imita- 
tors ;  and  to  imitate  is  still,  with  many,  accounted  a 
cause  for  reproach. 

But  one  of  the  great  doctrinal  gains  of  recent  psy- 
chology has  been  the  recognition  that  we  are  all  imita- 
tive to  the  very  heart ;  that  imitation  is  not  a  mark  of 
the  few  and  of  the  weak,  but  is  really  a  deep  trait  upon 
which  we  may,  without  exaggeration,  say  that  society 
and  morality  itself  depend.  To  Tarde  in  France,  and 
to  Baldwin  and  Royce  in  this  country,  we  are  chiefly 
indebted  for  the  development  of  this  important  truth. 
And  it  is  largely  as  a  result  of  the  interest  they  have 
aroused  that  at  the  present  time  one  can  hardly  read 
a  page  of  psychology  without  perceiving  some  appre- 
ciation of  the  role  that  imitation  and  suggestion  play. 

Now  why  do  we  link  imitation  and  suggestion  in  its  connec- 
this  way  ?  It  is  because  they  actually  do  He  so  close  ^^°^  "^^"^^^ 
together  that  when  you  consider  either  one  of  them 

199 


200 


Experimental  Psychology 


you  are  inevitably  led  to  view  the  other.  Imitation, 
in  fact,  may  well  be  counted  a  special  form  of  sugges- 
tion. But  this  will  come  out  more  clearly  when  we 
have  run  over  some  examples  of  these  processes,  be- 
ginning with  the  simplest  and  most  familiar  forms. 
It  will  then  also  appear  that  even  hypnotism  is  inti- 
mately connected  with  the  processes  just  mentioned. 


Fig.  39.  —  I.  General  form  of  conductor's  movement.  II.  The  record  of 
the  subject's  hand.  B  and  E  represent  respectively  the  beginning  and 
end  of  the  movement.    The  arrow  shows  the  direction  of  facing. 


Examples  of 

involuntary 

imitation. 


Tracings  by 
the  hand. 


Cases  of  deliberate  and  voluntary  imitation  are  of 
much  less  psychological  importance  than  are  those  of 
the  opposite  sort  —  the  inevitable,  involuntary  falling 
into  the  ways  of  those  about  us,  with  which  we  are  all 
familiar.  In  the  laboratory  we  have  a  good  illustra- 
tion of  involuntary  repetition  when  another's  move- 
ment is  intently  observed.  If  a  simple  contrivance, 
something  like  a  planchette,  be  arranged  to  write  on 
smoked  paper,  we  may  obtain  a  record  of  the  move- 
ment of  one's  hand  as  another  traces  before  him  the 


Imitation  and  Suggestion  201 

outline  of  some  figure.  The  record  often  shows  that 
the  observer's  hand  has  roughly  followed  the  move- 
ment which  he  was  closely  watching.  In  Fig.  39 
the  outline  on  the  left  gives  the  course  taken  by  the 
conductor's  hand  in  one  such  experiment,  while  the 
right-hand  figure  is  taken  from  the  record  involuntarily 
made  by  the  subject's  hand  while  intently  observing 
this  movement.     In  this  and  the  records  below,  B  and 


I  II 

Fig.  40.  —  II  shows  a  combination  of  direct  and  reversed  imitation 
of  the  form  in  I. 


E  denote  respectively  the  beginning  and  the  end  of 
the  movement.  Figures  40  and  41  give  similar  pairs 
showing  an  interesting  variation ;  the  conductor's 
movement  is  imitated  partly  in  reverse  order,  while 
part  of  the  figure  is  a  direct  imitation.  Many  of  our 
acts  that  seem  almost  entirely  mechanical  or  physio- 
logical—  walking  or  laughing,  for  instance  —  are 
trained  and  modified  by  seeing  how  others  do  them. 


202 


Experimental  Psychology 


Those  who  have  heard  the  uncanny  laughter  of  deaf 
mutes  can  appreciate  what  our  own  laughter  would  be 
like  if  it  were  not  for  the  influence  of  social  custom  and 
good  form.  So  tricks  of  speech  or  of  gesture  persist 
in  certain  families  as  if  they  were  transmitted  by  direct 
inheritance,  although,  in  fact,  the  children  often  come 


I  II 

Fig.  41.  —  II,  imitation  of  I,  showing  in  part  a  direct  and  in  part 
a  reversed  imitation. 


How  the  sen- 
sible pattern 
affects  us. 


by  them  merely  through  imitating  their  parents  and 
one  another.  Now  in  all  those  acts  which  we  most 
readily  recognize  as  imitative,  it  is  obvious  that  some- 
body's manner  or  behavior  induces  the  like  behavior 
in  us.  And  the  way  in  which  the  one  person  affects 
the  other  is,  in  its  broader  outlines  at  least,  clear 
enough ;  it  is  not  by  some  immediate  physical  control 
that  I  am  influenced,  but  only  because  some  action 
attracts  my  attention  so  that  I  become  conscious  of 
it,  and  becoming  conscious  of  it,  I  find  that  I  invol- 


Imitation  and  Suggestion 


203 


untarily  do  the  same.  In  all  such  cases  an  actual 
physical  pattern  is  furnished,  and  the  observer  pro- 
ceeds to  copy  it. 

But  a  host  of  facts  show  that  it  is  not  always  neces- 
sary to  have  a  pattern  sensibly  before  us.  If  an  idea 
of  an  action  can  by  any  other  means  be  kept  clearly 
before  one,  his  conduct  will  be  influenced  by  it  quite  as 
well  as  if  it  were  not  a  mere  idea  but  were  somebody's 
real  action.  Several  psychological  experiments  illus- 
trate this.  If  a  person  be  made  to  stand  erect  under 
a  blackened  plate  of  glass  or  sheet  of  paper,  and  a 
wire  point  or  sharp  piece  of  wood  be  attached  to  his 
head  so  that  it  will  quietly  scratch  this  blackened 
surface,  the  swaying  of  his  body  will  be  recorded, 
and  even  when  he  tries  to  stand  motionless,  an  intri- 
cate, irregular  line  will  be 
formed,  in  appearance  not 
unlike  the  mark  left  on  an 
earthquake  recorder.  An 
example  of  such  a  record 
appears  in  Fig.  42,  where 
the  arrow  marked  F  gives 
the  direction  in  which  the 
subject  was  facing.  Now  the 
form  of  this  line  is  differ- 
ent under  different  mental 
conditions,  and  it  is  gen- 
erally observed  that  there  is 

a  tendency  to  movement  in  the  direction  of  the  object 
which  for  the  moment  may  be  claiming  the  subject's 
attention.  If  we  ask  him  to  think  intently  upon  some- 
thing which  he  knows  to  be  at  his  left,  his  whole  body 


A  sensible 
pattern  is  not 
absolutely- 
necessary. 


Illustrative 
experiments. 


Fig.  42.  —  Record  with  subject 
standing  under  a  smoked 
plate. 


P 


/ 


/ 


204  Experimental  Psychology 

begins  to  sway  toward  that  side.  In  Figs.  43  and  44 
the  part  of  the  record  up  to  the  point  marked  by  the 
small  arrow  shows  the  normal  movement  without  any 


Fig.  43.  —  The  effect  of  attention  to  an  object  in  the  direction  E. 

special  direction  of  attention.  The  subject,  whose 
eyes  were  all  the  while  closed,  was  then  told  to  think 
of  some  designated   object  in  the  direction  of  E\ 


Fig.  44.  —  Effect  of  attention  to  an  object  in  the  opposite  direction 
from  that  in  Fig.  43. 

the  immediate  change  in  the  record  shows  the  re- 
sult. And  not  only  is  the  body  as  a  whole  thus  influ- 
enced by  the  direction  of  attention,  but  similar  results 


Imitation  and  Suggestion  205 

are  obtained  when  we  experiment  with  movements 
merely  of  the  arm  or  hand.  All  of  this  has  long  been 
known  from  the  experiments  of  Professor  Jastrow 
working  with  his  recorder  called  an  **  automatograph."  ^ 
Faraday  had  years  before  arrived  at  somewhat  similar 
results  by  his  experiments  on  the  phenomena  of  table- 
moving.  He  found  that  with  the  usual  conditions  Bearing  on 
under  which  these  movements  occur  —  that  is,  with  a  ^^^J^-^wmg 

'  and  mind- 

circle  of  persons  having  their  hands  on  the  table  and  reading, 
intently  thinking  of  its  moving  in  a  certain  direc- 
tion—  each  person  involuntarily  and  unconsciously 
pushes  it  toward  the  goal.  By  means  of  an  appa- 
ratus of  levers,  he  demonstrated  that  a  considerable 
physical  force  was  really  though  unconsciously  ex- 
erted.2  At  the  present  day  we  are  familiar  with 
something  similar  in  those  games  which  depend  upon 
"muscle-reading,"  and  which  have  sometimes  been 
believed  to  illustrate  the  possibility  of  thought-trans- 
ference. Most  persons,  if  they  really  carry  out  the 
conditions  of  the  game  and  vividly  picture  to  them- 
selves the  object  that  is  to  be  found,  will  give  mus- 
cular signs  that  are  unmistakable  to  one  practised  in 
such  things.  The  "  thinker  "  either  urges  his  compan- 
ion gently  in  the  right  direction,  or  else  gives  negative 
signs  — withholds  his  companion  from  the  right  place, 
in  his  very  eagerness  not  to  betray  the  locality  selected ; 
and  this  check  is,  when  understood,  as  good  a  clew  as 

1  Cf.  the  chapter  entitled  "  A  Study  of  Involuntary  Movements,"  in 
his  Fact  and  Fable  in  Psychology,  Boston,  1900,  p.  397. 

2  Faraday,  "  Experimental  Investigation  of  Table-moving,"  Athe- 
nmum,  July  2,  1853,  cited  by  Scripture,  The  New  Psychology,  New 
York,  1897,  p.  253. 


2o6  Experimental  Psychology- 

is  needed.  And  even  in  those  cases  where  there  is 
no  direct  contact  and  consequently  no  possibility  of 
muscle-reading  in  the  ordinary  sense,  there  are  signs 
of  another  sort.  The  recent  experiments  of  two 
Danish  investigators,  Hansen  and  Lehmann,^  go  to 
show  that  much  of  the  alleged  transfer  of  thoughts 
might  be  accounted  for  by  hints  and  suggestions 
given,  for  instance,  by  changes  in  the  mere  breathing 
of  the  person  who  wishes  to  impress  his  thought  upon 
another.  All  this  indicates  how  responsive  the  body 
The  body  is  I  is  to  the  mental  state.  The  mere  idea  of  an  act  starts 
responsive  to/  ^  chain  of  ncrvous  processes  that  finally  make  the 

our  mental    I  ^  -^ 

states.         /  action  real.     Something  that  the  person  is  thinking  of 
suggests   the   peculiar  response.      The   behavior   is 
then  the  result  of  suggestion.      In  imitation  in  its 
commoner  sense ^  there  is  much  the  same  process; 
the  only  difference  is  that  the  pattern  is  not  origi- 
nated from  within.      The  suggestion  in  such  cases 
is  simply  more  external  and  less  an  inner  product 
of  our  own. 
But  why  does       But  if  it  be  true,  as  has  been  thought,  that  ideas 
s^ondTnaii     P^^^  ^^^^  ^^  readily  into  movements  and  thus  tend 
cases?  to  be  actualized,  why  do  we  not  do  all  things  whatso- 

ever that  occur  to  us  ?  One  of  our  constant  sources 
of  regret  is  the  inefficiency  of  so  many  of  our  good 
intentions,  and,  on  the  other  hand,  we  happily  do  not 
actually  perform  all  the  foolish  things  of  which  we 
think.    In  many  instances  of  this  kind,  however,  there 

1  "  Ueber  unwilkiirliches  Flustern,"  Philosophische  Studien,  Vol.  XI, 
p.  471- 

^  Both  Baldwin  and  Royce,  as  is  well  known,  use  the  term  "  imita- 
tion "  to  include  much  more  than  this. 


Imitation  and  Suggestion  207 

is  nothing  to  make  us  doubt  the  original  proposition 
that  anything  which  suggests  to  us  the  thought  of  an 
action  tends  thereby  to  bring  on  the  very  act  itself. 
When  the  thought  remains  without  its  proper  result, 
it  is  usually  not  because  there  is  no  power  in  it,  but 
rather  because  its  inherent  force  has  been  offset  by 
an  equal  or  greater  force  in  the  opposite  direction. 
The  act  does  not  take  place,  because  along  with  the 
thought  of  it  there  comes  the  notion  of  the  contrary 
action.  And  since  both  ideas  tend  to  realization,  and 
yet  both  cannot  be  realized  at  the  same  time,  they 
produce  a  deadlock,  and  apparent  passivity  is  the 
result. 

-    In  this  way  checks  are  brought   about,  and   the  importance 
development  of  such  checks  is  an  exceedingly  impor-  ^fcomi^ti- 
tant  thing.     If  it  were  not  for  the  free  and  immediate  choice 
rise  of  contrary  suggestions,  we  should  be  the  prey  ^™°"s^  ^^^* 
of  the  first  idea  that  occurred  to  us.     So  the  arrival 
of  contrary  suggestions  prevents  headlong  mechani- 
cal action,  and  gives  us  time  to  summon  our  wider 
experience  and  make  it  play  upon  the  problem  of  the 
moment,  and  action  becomes  deliberate  rather  than 
impulsive.     It  seems  to  me  erroneous  to  describe  the 
result  as  a  victory  of  one  idea  over  another  ;  they  do 
not  fight  it  out  among  themselves,  the  stronger  van- 
quishing the  weaker.     They  are,  rather,  both  can- 
didates   for    an   alliance  with   the   will.      There    is 
something  like  a   selection  by  us  from   the  various 
suggestions  that  arise;  we  cast  our  volitional  force 
on  the  side  of  one  of  them,  and  action  in  keeping 
with  it  takes  place. 

A  healthy  mental  Hfe  requires  that  there  should  be 


2o8  Experimental  Psychology 

a  free  rise  of  antithetic  ideas,  and  that  we  should 
prefer  and  emphasize  the  idea  which  seems  suitable. 
But  in  some  persons  these  safeguards  are  wanting. 
The  first  idea  presented  brings  with  it  no  opponents, 
or,  if  accompanied  at  all,  it  has  only  harmonious  asso- 
ciates, and  these  have  free  play.  Such  persons  are 
impulsive,  unhesitating,  unreflecting.  They  are  often 
most  efficient ;  but  much  depends  upon  the  kind  of 
ideas  first  in  the  field.  If  good  ideas  come  first,  the 
absence  of  hesitation  is  a  gain ;  but  if  the  ideas  that 
arise  are  unfit,  then  the  impulsiveness  results  in  loss. 
The  difficulty  in  the  case  of  impulsive  persons  is,  that 
the  teachings  of  experience  often  obtain  no  hearing 
at  all. 

Connection  It  is  but  a  short  step  from  such  common  and  nor- 
nlsrwith^^^'  ^^^  states  as  these  to  phenomena  which  at  first 
hypnotism,  appear  to  offer  nothing  but  disconnection  and  con- 
trast with  our  ordinary  consciousness.  The  various 
experiments  in  hypnotism  show,  on  an  exaggerated 
scale,  much  that  is  already  familiar  in  impulsive  per- 
sons. In  the  hypnotized  person  there  is  a  narrowing!^ 
of  the  field  of  consciousness,  so  that,  for  the  most 
part,  all  ideas  are  excluded  except  such  as  are  in  har- 
mony with  what  the  operator  calls  up  by  his  words  or 
signs ;  and  the  action  of  the  person,  because  spon- 
taneous contrary  suggestions  are  checked,  falls  into 
accord  with  what  has  taken  possession  of  his  mind. 
He  has  only  to  be  told  that  he  is  General  Washington 
or  Frederick  the  Great,  and  a  more  or  less  clever  im- 
personation results.  The  ideas  here,  as  in  a  simple 
impulsive  or  imitative  action,  work  themselves  out, 


Imitation  and  Suggestion  209 

unopposed,  into  acts.  The  peculiarity  of  the  hypnotic 
state  is  that  it  shows  the  operation  of  suggestion  in 
such  a  marked  degree  ;  and,  moreover,  the  ideas  from 
which  the  action  springs  are  usually  induced  from  _ 
without,  instead  of  arising  spontaneously  from  the  sub- 
ject's own  character,  as  is  often  the  case  with  impulse. 
There  is  estabhshed  a  strange  r^//^r/ between  two  per- 
sons, so  that  the  suggestions  offered  by  the  hypnotizer 
take  precedence  of  all  others,  and  whatever  spontaneity 
there  is  in  the  patient  is  merely,  as  it  were,  a  sponta- 
neous assistance,  a  ready  filling-in  of  the  bare  outlines 
offered  by  the  person  in  control.  The  action  itself, 
when  once  the  ideas  are  aroused,  flows  off  unhin- 
dered according  to  the  general  law  of  mind,  that  all 
ideas,  unless  positively  checked,  tend  to  be  expressed 
in  action.  The  ordinary  counter-suggestions  —  the 
doubts,  the  self-consciousness,  the  thought  of  the 
incongruity  of  the  situation,  all  that  usually  makes 
it  impossible  for  us  in  normal  life  to  enact  whatever 
occurs  to  us  —  these  are  in  some  way  kept  under  in 
hypnotism,  and  the  one  isolated  group  of  ideas  comes  / 
to  full  expression.  But  this  is  only  an  exaggerated 
form  of  what  occurs  in  ordinary  imitation  or  sugges- 
tion. In  these  cases,  too,  an  idea  has  forced  its  way 
to  the  centre  of  attention,  and,  excluding  all  rivals, 
makes  us  act  it  out.  At  bottom,  then,  suggestion  and  Hypnotism  is 
imitation  and  the  main  facts  of  hypnotism  are  all  one.  foj.^"o°"^u  - 
The  person  whom  we  involuntarily  imitate  is  one  who,  gestion  or 
to  some  extent,  has  hypnotized  us.  Something  in  his  ^"^^'^*^°"- 
bearing  or  character  puts  us  in  touch  with  him  ;  he  cap- 
tures our  attention,  and  before  we  know  it,  we  are  re- 
peating his  acts  or  manner.     In  the  case  of  imitation, 


2IO  Experimental  Psychology 

the  suggestion  is  offered  by  another  person's  conduct ; 
in  hypnotism  it  is  more  by  word  of  mouth.  But  the 
mere  difference  of  mode  of  introducing  the  effective 
idea  into  the  mind  of  the  subject  is  a  minor  matter; 
in  the  more  essential  features  —  that  one  person  can 
arouse  an  idea  of  an  action  in  another  and  have  it 
expressed  in  conduct  —  hypnotism  and  imitation  are 
one.  Suggestion  or  imitation  may,  with  this  under- 
standing, be  used  as  a  convenient  term  for  the  whole 
group  of  occurrences. 
Analogies  But  I  Cannot  drop  the  subject  of  hypnotism  without 

notk:^and^'^^  somo  further  illustration  of  its  kinship  with  our  normal 
normal ac-  bchavior.  "I  hypnotized  Mr.  J.  F.,"  writes  a  recent 
^^°°*  contributor  on  the  subject;  "with  one  resolute  com- 

mand I  made  him  cataleptic.  *  Rise,*  I  commanded 
him.  He  rose.  *  Walk ' ;  he  walked.  *  You  cannot 
walk  forward.'  He  tried  to  walk,  but  could  not.  *  You 
can  only  walk  backward.'  He  began  to  walk  back- 
ward." ^  But  this  is  only  an  extreme  form  of  what 
we  are  all  experiencing  every  day.  The  same  writer 
found  that,  without  hypnotizing  his  men  at  all,  they 
would  carry  out  in  a  more  or  less  direct  and  mechani- 
cal fashion  his  simple  commands.  And  so  it  is  in  the 
larger  world :  some  men  have  the  power  to  make 
their  companions  feel  themselves  capable  or  incapa- 
ble of  certain  things,  and  the  assurance  brings  about 
its  own  fulfilment.  In  many  cases,  men  need  only 
to  believe  that  they  can  do  a  thing,  and  they  can ;  if 
they  believe  they  cannot,  the  act  then  becomes  im- 
possible for  them,  —  a  truth  which  Professor  James 

1  Sidis,  The  Psychology  of  Sttggestion,  New  York,  1898,  p.  12.     For 
his  instances  of  suggestion  without  hypnotism,  vide  ibid.,  p.  35. 


Imitation  and  Suggestion  211 

has  turned  to  such  striking  account  in  his  remarkable 
essay,  The  Will  to  Believe} 

Even  those  curious  phenomena  of  post-hypnotic  Post-hyp- 
suggestion,  which  to  many  seem  absolutely  unique  J|°JJ^  sugges- 
and  unprecedented,  have  their  analogies  in  states  of 
mind  in  which  there  is  no  sign  of  the  ordinary  hyp- 
notic influence.  The  hypnotized  person  is  told  that 
he  is  soon  to  be  awakened,  and  thereafter,  at  a 
given  sign,  he  is  to  perform  some  specified  act  — 
open  the  window  or  walk  around  his  chair.  The 
person  is  awakened,  and  when  the  occasion  comes, 
although  he  is  unable  to  give  any  clear  reason  why 
he  should  do  so,  he  carries  out  the  suggestion.  He 
finds  it  more  comfortable  to  do  it  than  to  resist  the 
impulse.  Something  like  this  we  are  all  familiar  similar  to  in- 
with,  though  luckily  it  comes  but  rarely  and  then  ^^jsesand 
only  in  regard  to  the  more  trifling  things  of  life,  ideas. 
When  tired  or  nervous  we  may  be  reasonably  certain 
that  our  door  is  locked,  and  yet  can  get  no  peace  of 
mind  until  we  have  satisfied  ourselves  once  more 
by  actual  trial.  Or  the  phrases  Heldemnoral  and 
Sklavenmoral  flit  through  our  mind,  and  although 
we  are  not  at  the  moment  interested  the  least  in 
Hterature  or  ethics,  but  wish  most  of  all  to  fall  asleep, 
still  the  insistent  question.  Who  has  written  of  such 
things .?  is  there,  and  we  must  finally,  protesting 
all  the  while,  think  up  the  name  of  Nietsche.  Here 
the  performance  of  a  certain  act  —  the  recalling  of 
the  author's  name  or  going  to  the  door  —  is  some- 
how given  a  force  that  is  out  of  all  keeping  with 

1  In  his  The   Will  to  Believe  and  Other  Essays  in  Popular  Phi- 
losophy,  New  York,  1898. 


212  Experimental  Psychology 

the  value  or  reasonableness  of  the  act  itself.  We 
cannot  justify  our  obedience  to  the  suggestion  on  any 
ground  except  that  it  is  not  worth  while  to  keep  up 
the  struggle ;  that  the  quickest  and  simplest  way  to 
regain  tranquillity  is  to  yield  and  have  done  with  it. 
It  was  evidently  something  of  this  kind  that  com- 
pelled Dr.  Johnson,  as  Boswell  tells  us,  to  touch 
each  post  as  he  passed  it  on  the  street;  and  if  by 
chance  he  missed  one,  he  must  return  and  tap  it  be- 
fore he  could  proceed.^  We  cannot  in  all  cases  say 
why  an  idea  can  gain  such  prominence ;  in  some  in- 
stances, the  very  odiousness  of  the  suggested  act, 
however,  draws  our  attention  to  it,  and  our  efforts  to 
banish  it,  but  fix  it  more  firmly  in  the  mind.  Thus 
we  see  that  also  in  this  class  of  acts,  where  the 
performance  does  not  result  simply  because  there 
is  no  opposition  to  it,  as  in  so  many  cases  of  hyp- 
notism and  of  impulse,  but  because  of  the  burr-like 
tenacity  of  some  idea  which  refuses  to  be  dropped 
until  it  has  worked  its  way  through  —  this  abnormal 
kind  of  suggestion,  too,  is  merely  an  extreme  case  of 
what  is  going  on  in  our  minds  daily,  but  which,  by 
its  very  familiarity,  ceases  any  longer  to  attract  much 
The  physical  attention.  Even  the  actual  physical  changes  which 
s^ggition  ^^^  sometimes  produced  by  suggestion,  —  blisters  or 
have  ana-  scars,  for  example,  by  touching  the  skin  with  some 
mfrmaUife.     i^nocent  objcct,  like  smooth  glass,  with  the  remark 

1  For  other  authorities  and  details  in  Johnson's  case  and  for  a  num- 
ber of  similar  and  most  striking  instances  coming  under  his  personal 
observation,  see  Dr.  Hack  Tuke's  "  Zwangvorstellungen  ohne  Wahn- 
ideen,"  Zeitschrift  fur  Psychologie  und  Physiologie  der  Sinnesorgane^ 
Vol.  II  C1891),  p.  95. 


Imitation  and  Suggestion  213 

that  it  is  glowing  hot,^  —  even  these  are  not  without 
parallels  on  a  small  scale  in  relatively  normal  states 
of  mind.  We  can  make  our  skin  tingle  by  fixing 
our  attention  upon  some  portion  of  it;  and  sickness 
is  often  brought  on  by  one's  very  concern  for  his 
health. 

Returning  now  to  our  normal  life,  it  might  seem  Suggestion  is 
as  if  imitation  and   suggestion  had  only  to  do  with  J^ygf'"^^'"' 
physical    acts  —  movements   of    hands    or    feet,    or  motor  affair. 
variations  of  speech.     But  this  is  by  no  means  true. 
Numerous  observations  and  experiments  show  that 
our  more  inner  mental  life  is  fully  as  subject  to  the 
effects  of  imitation  or  suggestion  as  are  these  invol-  its  part  in 
untary  movements  of  the  body.      Half  of  what  we  ^rtr'n^^' 
see  and  hear  never  comes  in  through  our  senses  at 
all,  but  is  made  up  outright  —  suggested  by  scraps 
and  hints  that  do  come  in  through  our  eyes  and  ears. 
In  a  foreign  land,  when  the  mind  is  not  so  ready  to  \ 

fill  in  all  the  gaps  in  the  unfamiliar  language  we  hear,  i 

one  begins  to  appreciate  how  largely  in  our  mother-  \ 

tongue  the  mere  act  of  catching   the  sound  of   the  j 

words,  not  to  say  their  meaning,  is  a  matter  of  sug-  I 

gestion.     And  in  other  ways  we  can  see  that  as  soon  I 

as   things   grow   famiHar   and   suggestive,  it  is   im-  ? 

possible  ever  to  experience  them  again  in  their  naked  r 

reality;    what  the    bare    sense-impressions   call    up  i' 

to  us  becomes   interwoven   with   them,  and     these  | 

additions  can  with   difficulty  be  distinguished   from  ^.^.  in  visual       j;' 
what   is    original.      Thus,   without    experiment,   we  ^^^*^*  i 

should  hardly  expect  that   the  consciousness  of  the  r 

1  KrafFt-Ebing,  op.  cit,,  pp.  28  et  seq.  '. 


^H 


Experimental  Psychology 


Modification 
and  sup- 
pression of 
sensations. 


different  distances  at  which  objects  lie  from  us  is  not 
as  immediately  "  given  "  as  are  the  very  colors  or 
shadows  of  these  things.  And  yet  it  is  not;  this 
depth  effect  is  our  own  construction  suggested  by 
the  distribution  of  Hght  and  shade,  the  direction  of 
lines,  and,  also,  by  the  sensations  of  strain  and  move- 
ment in  the  eyes.  The  "  tactile  values  "  in  painting, 
(as  Berenson  well  calls  them),  and  in  all  our  visual 
experience,  is  thus  a  matter  of  suggestion. 

But,  beyond  the  mere  spatial  qualities,  the  very 
stuff  of  our  sensations  is,  by  a  kind  of  mild  hypnotic 
influence,  altered  or  suppressed.  It  took  centuries 
for  artists  to  see  that  the  shadow  on  a  colored  sur- 
face was  not  a  darker  tone  of  the  same  color,  but 
had  usually  something  in  it  of  the  complementary 
hue.  The  natural  preconception  as  to  what  the 
color  of  the  surface  ought  to  look  Hke,  from  hav- 
ing seen  it  in  a  clearer  light,  made  it  impossible 
to  see  the  thing  aright.  The  imaginative  filling-in 
of  the  "  bhnd-spot,"  which  exists  for  all  of  us  in  the 
field  of  view  of  the  single  eye,  shows  the  same  ten- 
dency. And  Tawney  by  his  experiments  on  the 
sense  of  touch  ^  has  brought  out  the  enormous 
change  that  will  be  produced  in  the  apparent  sensi- 
bility of  the  skin  when  one  is  led  to  expect  that  the 
sensibility  will  change.  So,  too,  if  letters  or  figures 
be  very  briefly  exposed  to  our  view,  it  is  impossible  for 
one  to  say  how  much  of  them  he  has  really  seen 
and  how  much  he  has  imagined.  What,  in  truth,  he 
does  see  gives  some  bent,  starts  the  process  of  sug- 


1  Tawney,  "  Ueber  die  Wahrnehmung  zweier  Punkte,"  etc.,  Philo- 
sophische  Studien,  Vol.  XIII,  p.  163. 


Imitation  and  Suggestion 


215 


gestion,  and  either  adds  to  the  original  sense-impres- 
sion, or  alters  it,  often  in  some  most  surprising 
way.  If  one  try  his  best  to  copy  a  simple  figure 
that  is  exposed  but  an  instant,  aiming  to  put  down 
nothing  that  is  not  assuredly  observed,  it  is  aston- 
ishing how  much  will  be  seen  that  is  entirely  at 
variance  with  the  figure  as  it  really  is.  The  accom- 
panying drawings  (Fig.  45)  give  some  hint  of  the  re- 
sults of  this  process 
of  subjective  dis- 
tortion, the  first 
column  giving  the 
originals  that  were 
actually  shown, 
while  the  others 
are  the  careful 
drawings    of  what 

various   people  felt  ^^^^  45. -column   O  gives  original  figures 

sure       they       Saw.^  very  briefly  shown.    The  other  columns 

T.  -      ^  .,,      .              ,  show  how  these   appeared  to  different 

Most  illusions,  also,  observers. 

are  illustrations  of 

this  trait  of  adding  in  items  subjectively  at  the  insti- 
gation of  custom.  The  impossibility  of  distinguish- 
ing fact  and  fancy  by  any  difference  of  vividness  or 
of  sense  of  reality  is  what  makes  human  testimony 
upon  matters  of  fact  so  untrustworthy  and  so  much 
in  need  of  sifting  and  control.  Every  judge  and 
every  juryman  should  take  a  course  in  the  psycho- 
logical laboratory  to  appreciate  this  fully.  Experi- 
ence gives  us  our  twists  and  prejudices,  and  under  its 


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1  From  unpublished  experiments  by  Mr.  F.  G.  Athearn  in  the  labo- 
ratory of  the  University  of  California. 


2i6  Experimental  Psychology- 

moulding  power  the  outer  impressions  take  on  vari- 
ous forms.  With  all  of  us  it  is  as  it  may  have  been 
with  Polonius  when  Hamlet  questioned  him  :  — 

"  Hamlet.     Do  you  see  yonder  cloud,  that's  almost  in  shape 
of  a  camel? 

Polonius,     By  the  mass,  and  'tis  like  a  camel,  indeed. 
Ham.     Methinks,  it  is  like  a  weasel. 
Pol.     It  is  back'd  like  a  weasel. 
Ham.     Or,  like  a  whale? 
Pol.    Very  like  a  whale." 

Suggestion  But  it  is  not  in  altering  the  play  of  our  perceptions 

may  deter-      nierelv  that  sufiTgestion  makes  itself  felt.      We  find 

mine  our  •'  °° 

preferences,  that  our  deeper  processes,  too,  are  under  its  control. 
Our  momentary  interest,  our  sense  of  the  relative 
value  of  things,  is  largely  a  gregarious  matter ;  it  is 
induced  in  us  by  the  persons  who  form  our  society. 
On  a  small  scale  the  phenomenon  is  illustrated  by  the 
effect  which  a  single  person  gazing  intently  in  a  shop- 
window  will  have  upon  the  passers-by,  especially  in  a 
foreign  city,  where  doubtless  some  oddities  of  dress 
or  manner  heighten  his  suggestive  influence;  you 
may  select  the  most  unpromising  and  commonplace 
display  of  goods,  and  very  soon  have  quite  a  gather- 
ing of  persons  all  interested  in  the  sight.  It  is  not 
that  they  wish  to  solve  the  merely  intellectual  prob- 
lem of  what  it  is  that  you  find  interesting  there ; 
your  own  attitude  is  catching,  is  involuntarily  imi- 
tated, and  excites  its  appropriate  mental  state  in  them. 
The  prevalence  of  styles  in  dress,  that,  when  the  spell 
is  off,  look  Hke  an  invention  of  the  feeble-minded, 
illustrates  the  same  fact.     And  probably  the  effec- 


Imitation  and  Suggestion  217 

tiveness  of  ordinary  commercial  advertisements  lies 
less  in  the  fact  that  they  add  to  our  knowledge  about 
certain  goods  than  that  they  simulate  the  voice  of  a 
wide  circle  of  persons  all  interested  in  that  particular 
ware  and  commending  it ;  and  when  throughout  the 
community  we  seem  to  find  such  warm  approval,  we 
ourselves  look  with  less  distrust  at  the  article  offered 
and  finally  come  to  be  among  the  buyers.  Adver- 
tisements are  effective  because  they  produce  an  illu- 
sion of  social  approval.  We  are  all  subject,  more  or 
less,  to  the  influence  of  "  movements  "  or  fads.  Some 
become  interested  thereby  in  Japanese  woodcuts, 
while  others  take  to  the  study  of  sociology  or  Bud- 
dhism ;  but  whatever  may  be  its  form,  it  is  an  induced 
interest,  and  a  state  of  mind  that  would  be  impossible 
were  we  not  subject  to  contagion  from  those  about 
us.  The  action  of  a  mob  that  performs  deeds  that 
any  solitary  member  would  shrink  from,  is  but  the 
last  and  fiercest  development  of  the  influence  which 
suggestion  may  have  upon  the  single  individual. 

But  the  mental  effect  of  suggestion  or  imitation  is  Nor  is  its 
by  no  means  always  transitory,  nor  has  it  chiefly  to  ^^ansitor^^^^ 
do  with  our  hurried  interests  and  inclinations.     Our 
cool  judgment,  our  taste,  our  affections,  are  perma- 
nently altered  in  this  way.     Through    imitation,  we  its  r6ie  in 
each  come  to  possess  much   of  what   humanity  has  veionrntift^" 
accumulated.     Not  only  does  the  child  obtain  largely 
through  imitation  the  power  of  speech,  with  all  the 
store  of  conceptions  which  that  implies,  but  his  pref- 
erences and  interests,  which  make  it  possible  for  him 
in  later  life  to  work  with  his  fellows,  are  gradually 
influenced  by  the  constant  presence  of  like  prefer- 


velopment 


:2i8 


Experimental  Psychology 


.  ences  in  his  society.  The  interest  of  his  parents  in 
I  him  is,  as  Professor  Baldwin  has  lately  shown,  one 
J  of  the  main  sources  of  the  child's  consciousness  of 
himself.  The  process  here  is  but  a  more  important 
case  of  what  we  have,  in  a  trivial  way,  in  the  shop- 
window  experience  already  referred  to.  The  inter- 
est of  others  excites  our  interest  in  the  same  thing ;  so 
the  child  begins  to  take  account  of  himself  largely  by 
marking  the  attention  with  which  the  circle  of  the 
family  regard  him.  He  must  take  notice  of  that 
centre  to  which  their  eyes  are  so  constantly  directed. 
His  further  education  is  very  much  a  matter  of  ex- 
ample, which  is  but  another  way  of  saying  that  it 
in  teaching;  is  mainly  guided  by  imitation.  The  teacher's  most 
searching  work  consequently  lies  in  furnishing  a  pat- 
tern of  right  interests  and  right  appreciation  of  things, 
so  that  like  attitudes  of  mind  shall  be  stimulated  in  the 
child.  Much  of  our  respect  for  men  comes  because 
in  morality,  we  scc  that  Others  respect  them,  and  this  proper  recog- 
nition of  their  presence  is  one  of  the  foundations  of 
morality  and  religion.  The  teacher  may  possess  most 
approved  pedagogical  devices,  and  be  thoroughly  mas- 
ter of  the  subject  to  be  taught ;  but  if  at  bottom  he  be 
bored  by  his  work,  nothing  will  quite  prevent  the  child 
from  being  insensibly  affected  in  the  same  way.  And, 
on  the  other  hand,  it  is  due  to  the  direct  contagion  of 
states  of  mind  that  the  enthusiast,  ill-equipped  and 
clumsy  though  he  may  be,  is  often  so  successful  in 
dealing  with  the  young.  This  immediate  effect  of 
personality  is,  too,  the  reason  why,  in  spite  of  printing- 
presses  and  books,  the  world  is  not  yet  ready  to  abol- 
ish the  pulpit  or  the  professor's  chair.     Better  things 


Imitation  and  Suggestion  219 

than  one  hears  from  most  of  them  are  to  be  found  on 
any  shelf,  and  yet  we  rightly  prefer  the  person  to  the 
book,  because  the  words,  reenforced  by  a  living  pres- 
ence, arouse  the  imitative  powers  within  us  in  a  way 
that  mere  print  can  never  do.  There  is  much  sound  Psychology 
psychology  in  some  of  the  old  dogmas  of  the  Catholic  ^^  religious 
church  which  Protestants  are  often  inclined  to  regard 
as  empty  formulas.  The  stress  laid  on  the  power  of 
the  church  —  on  the  efficacy  of  personal  fellowship,  in 
contrast  with  the  supposed  power  of  certain  documents 
or  impersonal  doctrines  —  is  in  entire  keeping  with  the 
modern  perception  of  our  dependence  on  example. 
The  tradition  must  be  personal  rather  than  mechan- 
ical; there  must  be  a  spiritual  laying  on  of  hands. 
And  again,  our  appreciation  of  the  value  of  imitation 
makes  one  see  what  deep  truth  there  is  incrusted  in  an- 
other of  their  doctrines — that  the  goodness  of  the 
saints  is  available  for  others.  Not  only  is  it  available, 
but  whatever  gain  most  of  us  make  is  by  a  kind  of 
spiritual  appropriation  of  what  others  have  already  at- 
tained. Through  imitation  the  gains  of  one  become 
a  common  possession,  without  loss  to  him  who  first 
made  the  gain ;  it  is  multiplied  in  those  who  avail 
themselves  of  it.  But  the  facts  themselves  are 
even  wider  than  the  ecclesiastical  doctrine;  for  the 
possibility  of  appropriating,  through  imitation,  the 
attainments  of  another  is  not  simply  a  matter  of 
morals  or  religion,  in  their  stricter  limits;  it  runs 
through  all  our  life,  through  all  planes  of  our  in- 
tellectual growth,  and  even  down  to  our  bodies  them- 
selves, into  our  very  muscles  and  sinews.  We  should 
all  be  stronger  of  body  if  we  could  have  only  robust 


220  Experimental  Psychology 

associates,  and  few  can  stand,  without  physical  loss, 
the  constant  presence  of  invalids. 

The  sinister  And  this  leads  to  the  fact  that  there  are  two  sides 
fmhTtion.  ^^  imitation :  the  one  beneficial,  the  other  just  the  re- 
verse. There  is  a  fascination  in  evil  acts  that  causes 
them,  also,  to  be  repeated,  quite  as  truly  as  in  those 
of  the  opposite  kind.  Indeed,  at  the  present  day,  it 
is  this  dangerous  aspect  of  suggestion  that  has  popu- 
larly been  most  emphasized.  Not  only  is  it  often 
thought  that  imitation  leads  men  to  reproduce  the 
bad  pattern  quite  as  frequently  as  the  good,  but  the 
very  fact  that  anything,  good  though  it  be,  has  come 
about  at  the  suggestion  of  another,  is  felt  to  take 
somewhat  from  its  merit.  It  is  a  sign  of  weakness, 
of  want  of  originating  power;  in  so  far  as  we  are 
imitative  we  are  dependent  upon  others  and  cannot 
guide  them,  but  must  be  led.  And  so,  too,  in  regard 
to  hypnotism :  the  specialist  is  inclined  to  view  it  as 
a  beneficial  power,  something  to  be  used  for  the  cure 
of  the  sick ;  but  the  more  widespread  attitude  toward 
it  is,  rather,  one  of  mistrust  and  alarm.  The  appear- 
ance of  hypnotism,  occasionally,  in  the  courts  and  in 
tales  like  that  of  "  Trilby  "  has  hinted  at  the  possibili- 
ties of  evil  in  it.  There  are  those  who  hold  that,  ex- 
cepting perhaps  the  use  of  hypnotism  in  the  cure  of 
the  body,  its  presence,  whether  for  good  or  evil,  is  a 
disquieting  thing ;  it  shows  that  we  are  in  the  power 
of  others,  whereas  the  only  way  to  be  secure  is  to  be 
entirely  self-poised,  after  the  manner  of  the  ancient 
stoics. 

For  those  who  dislike  the  thought  of  dependence 


Imitation  and  Suggestion  221 

upon  others,  there  really  is  no  comfort  in  the  univer-  From  our 
sal  influence  of  imitation  and  suggestion.  The  pres-  recehrg  ^oth 
ent  appreciation  of  their  significance  is  decidedly  good  and 
against  the  stoic  ideal  of  a  soul  perfectly  self-cen-  ^^^** 
tred,  and  also  against  the  somewhat  similar  Romantic 
ideal  of  a  free  and  wayward  personality  developing 
entirely  from  within,  taking  no  cue  or  hint  from 
those  about  him.  In  laying  stress  upon  the  imitative 
function,  our  modern  psychology  is  really  furnishing 
excellent  support  for  a  socialistic,  rather  than  an  in- 
dividualistic, view  of  man.  The  doctrine  of  Leibnitz, 
in  which  each  monad  is  shut  off  from  influences  from 
without,  developed  solely  by  an  inner  force,  mirror- 
ing the  universe,  but  standing  in  no  vital  relation 
to  the  other  members  of  the  system  —  all  this  is 
certainly  unpsychological  according  to  our  present 
light.  Whether  we  prefer  it  or  not,  there  can  be  no 
doubt  that  in  our  mental,  as  in  our  physical  life  there 
is  no  possibility  of  isolation  and  solitary  development. 
From  our  fellows,  we  receive  both  good  and  evil ;  our 
fate  to  a  large  extent  is  in  their  hands. 

In  many  ways,  indeed,  this  recognition  of  the  essen-  Respon- 
tially  social  character  of   man,  which   is  thus  reen-  ^^^g^^^*^  ^l^_^^ 
forced  by  psychology,  is  a  wholesome  thing,  even  for  dangered. 
our  morals.     To  some  the  danger  seems  to  lie  in  the 
fact  that  we  are  all  the  while  discovering  how  little 
the  individual  is  master   of   the   situation,  and  how 
little,  therefore,  must  be  his  responsibility.    If  in  a 
certain  sense  we  are  all  in  the  hypnotic  power  of  our 
fellow-men,  —  if   they  do,  in   a  degree,  cast  a  spell 
over  us  and  make  us  do  their  bidding,  —  I  am  not 
sure  that  the  situation  is  one  whit  worse  than  in  the 


222  Experimental  Psychology- 

older  view,  where  each  man  was  an  independent  unit, 
bound  by  no  living  tie  to  those  about  him.  If  my 
neighbor  is  not  dependent  upon  me,  and  I  cannot  to 
some  extent  determine  what  his  fate  shall  be,  I  can 
The  servant  feel  uo  responsibility  for  him.  It  is  as  we  have  found 
IS  also  lord.  ^^  politics  I  the  Only  way  to  throw  responsibility  on 
any  one  is  to  give  him  power.  The  difficulty  is  that 
we  are  inclined  to  look  at  the  dependence  as  exist- 
ing in  only  one  direction.  We  think  of  the  mental 
life  of  the  individual  as  swayed  by  the  suggestions 
of  his  fellows,  and  overlook  the  fact  that  he,  too,  is 
a  centre  from  which  flows  a  counter  quasi-hypnotic 
influence ;  he,  too,  is  controlling  them.  His  respon- 
sibility, which  is  in  a  way  diminished  when  we  regard 
him  only  as  the  recipient  of  influences,  is  restored 
when  we  see  that  he  gives  as  well  as  takes ;  and  that 
since  he  inevitably  influences  others,  he  must  answer 
for  the  effect  which  he  produces. 

Originality  So  that  imitation  is,  after  all,  but  one  side  of  the 

and  imitation  jxicutal  proccss.     The  Other  side  is  orisrination,  which 

are  insepa-  ,      ^  . 

rabie.  is  quite  as  real  and  demonstrable  as  imitation  itself. 

Imitation  is  a  mere  schoolmaster  to  bring  us  to  origi- 
nality. The  child,  through  imitating  others,  becomes 
aware  of  his  own  capacity  for  a  wide  variety  of  acts 
that  he  otherwise  would  have  believed  were  beyond 
his  powers ;  he  finds  that  he  is  able  to  do  what  others 
do.  In  this  way,  his  own  strength  and  skill  and  ver- 
satility are  not  only  cultivated,  but  are  revealed  to 
■  himself.  Imitation,  then,  even  when  we  slavishly 
copy  the  acts  of  those  near  us,  is  all  the  while  teach- 
ing us  our  own  capacity.     But  even  in  the  earliest 


.  Imitation  and  Suggestion  223 

years  we  are  never  quite  so  slavish  as  we  might  be- 

Heve.     All  patterns  do  not  appeal  to  us  with  equal 

force.     While  it  is  true  that  the  prototypes  of  most 

of  the  child's  acts  can  be  found  in  the  conduct  of 

those  about  him,  yet  it  is  also  true  that  a  great  many 

things  are  done  in  his  presence  which  he  does  not 

imitate  at  all ;  and  this,  of  course,  is  especially  true 

in  later  life.     Our  individuality  is  revealed  in  a  sort  Our  selection 

of  selection  of  the  persons  and  kinds  of  behavior  that  o^thepat- 

^  tern  to  be 

shall  have  power  over  us.  I  do  not  mean  that  the  imitated, 
selection  is  always  voluntary,  nor  is  it  consciously 
worked  out.  But  there  is  something  in  us  that  we 
cannot  attribute  to  mere  environment  —  an  inner 
stamp  or  character  that  makes  some  persons  have 
weight  with  us  while  the  behavior  of  others  takes  no 
hold.  We  find  our  affinities,  we  make  our  choice  of 
the  various  forms  of  conduct  that  are  offered  us. 
Thus  with  the  same  set  of  companions  we  find  one 
particular  child  picking  out  whatever  of  mechanical 
skill  he  finds  in  the  company.  He  immediately 
seizes  on  their  power  to  construct  steam-engines 
or  to  use  tools,  and  whatever  any  of  his  fellows 
can  do  in  this  way  he  imitates  and  makes  his  own. 
Another  boy  gathers  in  from  the  same  playmates 
an  entirely  different  set  of  accompHshments ;  upon 
him,  the  machinery  part  of  their  interests  makes 
no  impression,  but  all  suggestions  they  offer  which 
tend  toward  the  collecting  of  things  affect  him 
readily,  and  habits  of  accumulation  and  trade,  rather 
than  of  invention  and  construction,  are  thus  encour- 
aged. No  individual  is  absolutely  plastic  in  the 
hands  of  his  fellows;  he  soon  shows  his  own  grain. 


224 


Experimental  Psychology 


Even  the 

hypnotized 

subject 

reveals 

personal 

traits. 


Originality 
even  in  fol- 
lowing copy. 


Even  the  hypnotized  subject  carries  out  some  sug- 
gestions better  than  others.  So  that  the  individual 
is  not  a  mere  recipient,  a  transmitter  of  whatever 
influences  come  his  way,  but  has  within  him  a  power 
which  stands  over  against  his  environment  and  treats 
with  it  on  equal  terms,  now  aiding  and  heightening 
its  particular  influence,  and  now  resisting  the  sug- 
gestions which  it  offers. 

But  the  inner  power  of  the  individual  is  displayed 
not  only  in  his  choice  of  the  various  patterns  that  are 
presented  to  him  for  imitation,  but  also  in  his  free 
treatment  of  the  copy  which  finally  counts.  Very 
rarely  do  we  find  a  literal  repetition  of  what  is 
offered.  Even  from  the  beginning  there  is  a  ten- 
dency to  depart  a  little  from  the  copy  —  to  adapt  it 
somewhat  to  the  special  circumstances  and  tastes  of 
the  individual ;  so  that  the  repHca  always  has  a  turn 
in  it  that  the  original  did  not  have.  The  person, 
thus,  in  imitating,  contributes  something  out  of  his 
own  character ;  a  novel  element  is  introduced  which 
strikes  the  attention  of  those  about  him ;  and,  if  it 
accords  with  their  own  natures,  is  repeated  by  them 
and  further  modified  and  supplemented.  The  very 
unexpectedness  of  it  makes  it  a  more  fascinating 
thing  and  increases  its  power.  So  that  the  differ- 
ence which  we  notice  in  the  power  of  individuals  to 
compel  us  to  follow  their  example  depends  mainly  on 
the  difference  in  the  amount  of  this  originality  which 
their  acts  reveal.  So  far  as  the  individual  is  a  mere 
puppet,  his  example  counts  for  nothing.  Imitation 
is  thus  always  a  recognition  of  original  force  and 
worth  in  the  person  who  influences  us ;  it  is,  as  the 


Imitation  and  Suggestion  225 

proverb  says,  the  sincerest  flattery.  It  springs  from 
power,  and  is,  therefore,  not  a  sign  merely  that 
human  nature  is  weak  and  plastic,  but  an  indication 
as  well  that  human  nature  has  force  and  will. 

And  of  course  the  world  is  not  divided  into  two  The  genius 
classes,  those  who  imitate  send  those  who  influence  f.^^^^^ 

'  times. 

Others.  But,  rather,  each  person,  be  he  genius  or  be 
he  dolt,  is  in  some  degree  both  imitator  and  pattern. 
In  some  things  he  allows  others  to  lead  the  way; 
in  some  things  he  is  an  example  to  them.  And  even 
the  genius  is  an  imitator,  while  he  is  putting  himself 
in  possession  of  the  accomplishments  of  his  times; 
but  having  learned  his  trade  in  this  way,  he  goes 
beyond  his  teachers.  Genius,  for  this  reason,  does 
not  produce  isolated  and  unprecedented  work,  but 
comes  as  a  culmination  of  much  partially  successful 
striving  on  the  part  of  others  working  in  the  same 
line.  They  give  him  what  they  can,  and  he  caps 
their  work.  He  is,  thus,  neither  the  product  of  his 
times,  nor  is  he  independent  of  them.  His  general 
aim  is  more  or  less  induced  in  him  by  his  companions, 
and  from  them  he  learns  his  craftsmanship ;  but  he 
finally  outstrips  them  and  sets  a  mark  which  the 
others  are  unable  to  surpass. 

There  is,  then,  no  real  conflict  between  the  imita-  Man  is  at 
five  tendency  and  the  desire  to  be  a  source  of  power.   °e^^and  the°*' 
Only  through  the  play  of  others  upon  us  do  we  come  clay. 
into  possession  of  our  faculties.     Imitation  thus  paves 
the  way  for  its  own  destruction.     It  is  a  kind  of  go- 
cart    in   which    the   infant    mind    learns    finally   to 
walk  alone.     The  knowledge  of  these  psychological 
factors  thus  brings   out   clearly  how  social  and  yet 


226  Experimental  Psychology- 

how  personal  a  being  man  is;  for  even  his  origi- 
nality is  induced  by  others ;  and,  still,  his  imitations 
are  in  a  way  his  own.  Only  by  his  inner  power  can 
he  ever  be  open  to  suggestions  from  others ;  a  stone 
cannot  be  hypnotized.  We  must  keep  the  two  as- 
pects of  suggestion  before  us  in  due  proportion.  We 
must  not  think  that  the  individual  mind  is  mere  clay 
in  the  hands  of  society.  Nor,  on  the  other  hand, 
can  we,  when  we  fully  understand  the  import  of 
imitation,  ever  believe  that  society  is  an  accidental 
thing,  and  that  the  individual  grows  solely  by  a  force 
from  within. 


CHAPTER  XII 

THE  ENJOYMENT  OF   SENSATIONS  AND  THEIR 
FORMS 

Whatever   psychology  may  offer  in    regard   to  ^Esthetics  vj. 
beauty  must  not  be  considered  as  competing  in  any  ^hobgy  of 
way  with  the  philosophy  of  art.     The  psychological  beauty, 
work  here  has  not  the  same  aim  that  aesthetics  has ; 
it  is  concerned,  first  and  foremost,  with  scientific  ex- 
planations rather  than  with  standards  of  judgment  or 
appreciation.     It  is  for  aesthetics  to  define  what  art 
and  beauty  are,  to  determine  what  qualities  a  work 
shall  have  if  it  is  to  be  counted  a  work  of  art ;  psy- 
chology is  busied  with  a  very  different  problem, — 
how  it  is  that  things  of  beauty  produce  their  pleas- 
urable effect. 

The  psychology  of  the  beautiful,  then,  remains  far  General 
from  some  of  the  deepest  problems  of  art.  To  jj^g^^ork^^^ 
one  who  is  chiefly  interested  in  this  other  — 
the  philosophical  —  side,  the  experimental  studies 
are  apt  to  give  as  little  satisfaction  as  would  a 
chemist's  report  of  the  pigments  used  in  the  Sistine 
frescos,  or  a  mineralogist's  examination  of  the  stone 
in  the  Victory  of  Samothrace.  The  psychological 
work  is  explanatory  rather  than  appreciative,  and,  as 
yet,  has  to  do  with  the  bare  rudiments  of  the  artist's 
work — with  such  matters  as  symmetry  and  proportion, 

227 


228 


Experimental  Psychology- 


why  the  ex- 
periments 
seem  to 
slight  the 
masterpieces 
of  art. 


Beauty  must 
first  be  di- 
vided into  its 
elements. 


with  rhythm,  harmony,  and  the  Hke.  And  even  in  the 
experimental  study  of  these,  only  a  beginning  has 
been  made.  But  this  beginning  is  interesting,  and 
already  gives  indications  of  where  the  final  truth  will 
be  found. 

It  might  seem  at  first  sight  that  the  experimental 
method  could  most  profitably  be  applied  directly  to 
great  products  of  art  like  the  Elgin  marbles  or 
Bach's  Passion  Music.  Why  not  set  before  a  person 
a  work  of  this  kind  and  note  the  character  of  his 
"  reaction " .?  Is  not  every  artist,  indeed,  in  some 
such  way  an  experimenter  in  the  realm  of  pleasure  ? 
In  a  sense,  yes ;  but  not  within  the  scientific  meaning 
of  the  word  "  experiment."  For  in  scientific  work  it 
has  been  found  that  experiments  are  of  value  only  in 
so  far  as  the  conditions  of  the  experiments  are  rela- 
tively simple.  One  must  not  experiment  with  the 
universe  in  general,  but  must  select  from  the  confus- 
ing whole  some  single  factor  and  discover  what  is  its 
pecuhar  force.  In  any  great  work  of  art  too  many 
elements  combine,  and  one  cannot  say  how  much  of 
the  total  result  is  to  be  attributed  to  any  one  of  them. 
The  effect  which  the  "  Fates "  of  Phidias  produces 
upon  us  is  due  not  alone  to  the  material  used,  and 
to  the  graceful  curves  which  represent  the  figures 
and  the  drapery,  but  to  the  numberless  suggestions 
which  these  arouse,  —  the  times  of  Pericles,  the  Par- 
thenon, and  the  placid  Greek  religion.  And  each 
of  these  factors  again  contains  in  reality  a  mul- 
titude of  subordinate  elements.  So  that  it  is  im- 
possible to  deal  in  strict  experimental  fashion  with 
objects  which  excite  us  in  so  many  different  ways. 


The  Enjoyment  of  Sensations  229 

We  must  begin  at  the  very  beginning,  with  the  very 
alphabet  of  beauty,  and,  if  possible,  gain  some  insight 
there  into  the  nature  of  its  effect  upon  us. 

Beginning,  then,  with  the  simplest  materials  of  i.  The  ma- 
beauty,  it  is  found  that  with  children  colors  have  {,^eTl^°^ 
different  emotional  values  even  at  an  early  age.  It 
is  not  as  yet  entirely  clear  just  what  colors  are  most  Color 
attractive  to  the  infant;  the  results  of  experiments 
conflict,  and  probably,  as  with  adults,  there  are  indi- 
vidual differences.^  But  on  the  whole  it  is  probable 
that  the  reds  and  yellows,  which  Goethe  in  his 
study  of  colors  found  so  stimulating  and  which  the 
savage  so  much  enjoys,  are  also  preferred  by  most 
babes.  They  react  more  promptly  or  strongly  to 
these,  or  select  them  from  among  others.  Blue  and 
green,  which,  as  mere  impressions,  are  quite  as 
marked,  quite  as  vivid,  in  their  way,  as  are  red  and 
yellow,  evidently  have  not  the  charm  for  the  primi- 
tive and  childish  nature  that  these  warmer,  sunnier 
hues  possess.  Their  very  association  with  warmth 
and  vigor   may  in   some   degree   contribute  to   this 

1  One  of  the  sources  of  this  conflict  in  experimental  results  is  (in 
addition  very  likely  to  the  personal  equation  of  the  babes)  doubtless 
some  lack  of  critical  agreement  as  to  the  signs  of  color  preference  here. 
The  mere  power  to  name  or  to  become  attentive  to  a  color,  for  example, 
has  at  times  been  taken  as  an  indication  that  the  color  gave  a  peculiar 
pleasure.  It  could  hardly  be  maintained,  however,  that  a  child's 
readier  notice  of  a  loud  noise  was  proof  that  this  sound  was  preferred 
to  one  of  more  moderate  intensity.  In  the  end,  perhaps,  the  chief 
reliance  will  have  to  be  upon  the  more  subtle  signs  of  enjoyment,  on 
which  Miss  Shinn  mainly  depended.  (See  her  "  Notes  on  the  Devel- 
opment of  a  Child,"  University  of  California  Studies^  Vol.  I,  pp.  '^t, 
and  50.) 


I 


230  Experimental  Psychology 

effect;  but  doubtless  the  comparative  rarity  of  the 
experience  is  an  element  in  the  case.  Gold  and  red 
and  yellow  find  the  senses  unjaded,  since  these  colors 
are  not  constantly  present ;  while  the  blue  sky  and 
the  green  foliage  are  always  near.  The  preference 
in  these  cases  is,  however,  not  solely  sensuous ;  it  is 
not  alone  that  the  eye  is  unwearied  by  such  tones; 
there  is,  besides,  the  intellectual  stimulation,  the 
interest,  which  uncommon  things  always  give.  The 
savage  and  the  child  seem,  also,  to  prefer  the  satu- 
rated and  unmixed  color,  while  we  in  our  art  incline 
to  some  softening  and  breaking  of  hues,  —  for  in- 
stance, blue  with  the  faintest  tinge  of  red  or  yellow,  — 
partly,  perhaps,  from  a  desire  to  imitate  the  colors  of 
nature,  which  are  never  pure,  but  partly,  it  may  be, 
to  make  the  color  less  easily  classed,  more  problem- 
atical, so  that  it  may  better  hold  the  attention.  The 
color  in  tapestries,  the  mellowness  of  the  old  masters 
of  painting,  gives  pleasure  of  this  kind.^ 

In  a  similar  way  the  purest  sounds  are  not  the 
ones  most  used  in  music.  The  tuning-fork,  after  the 
first  noise  of  the  stroke  is  past,  gives  a  tone  like  a 
pure  color  of  the  spectrum  ;  it  is  well-nigh  absolutely 
unmixed.  The  absence  of  this  kind  of  tone  from 
our  music  may  be  due  in  part  to  mechanical  diffi- 
culties in  avoiding  the  initial  harshness  when  the 
tone  is  struck,  or  to  the  impossibility  of  easily  varying 

1  Professor  Jastrow,  from  results  obtained  at  the  Chicago  World's 
Fair,  finds  that  men,  in  their  color  preference,  run  to  blue,  women  to 
red.  Among  children,  blue  is  far  less  acceptable  than  pink.  "  The 
Popular  ^Esthetics  of  Color,"  Popular  Science  Monthly^  Vol.  L, 
p.  361. 


The  Enjoyment  of  Sensations  231 

its  time  and  strength,  but  there  are  probably  deeper 

reasons  as  well.     For  the  flute,  which  also  gives  a 

relatively  simple  and  pure  tone,  seems  characterless 

in  the  main.     The  tones  that  please  us  most  —  those 

of  the   human    voice,  the    organ,    the    violin  —  are 

always  tinged  with  other  tones,  have  in  them  a  shade 

of   impurity,   some   dim   suggestion   of   mere   noise. 

But  this   foreign   element  never  obtrudes  itself;    it 

never  appears  in  its  own  behalf ;  it  serves  only  as  a 

kind  of  atmosphere  to  enrich  what  is  seen  through  it. 

The  note  must  interest,  must  baffle  us  somewhat,  or 

we  reject  it  as  tame.     So  that  even  down  in  the  sim-  Faint  signs 

pie   sensations   of   sound   as   well   as  of   color,   the  of  a  union  of 

^  ^  ^  '  sensation 

pleasure  is  due  in  part  to  the  presence  of  some-  with  a  non- 
thing  in  contrast  with  the  mere  sensations  —  is  due  ^g^t^^"^  ^^^" 
to  the  conjunction  of  sensation  with  (if  we  shall  not 
be  misled  by  the  word)  a  "  formal "  element,  as  well. 
The  simplest  sensory  part  of  art,  its  materia  prima^ 
already  begins  in  this  way  to  show  faintly  the  marks 
that  are  so  characteristic  of  the  finished  work, 
—  the  contrast  of  the  materials,  on  the  one  hand, 
and,  on  the  other,  the  order  or  form  in  which  the 
materials  are  arranged.^ 

1  The  scholastic  distinction  of  "  matter  "  and  "  form  "  that  is  so  pro- 
nounced in  this  chapter,  and,  indeed,  runs  more  or  less  throughout  the 
entire  book  (although  not  always  in  these  words),  is  not  intended  to 
imply  that  the  two  are  separate  or  separable  realities.  The  present 
writer  sympathizes  with  the  objection  that  has  been  made  to  the  use 
of  these  terms,  —  that  the  two  factors  are  interdependent,  and  that 
either  alone  is  a  sheer  abstraction.  But  it  is  often  of  great  practical 
service  to  distinguish  things  that  are  inseparable,  and  an  abstraction  is 
not  necessarily  a  nonentity  nor  to  be  despised.  Pure  "  matter  "  and  pure 
"  form  "  are  two  opposite  limits  (in  a  quasi-mathematical  sense)  between 
which  a  concrete  reality  may  move,  now  approaching  the  one  pole  and 


232 


Experimental  Psychology 


II.  The 

elementary 
forms : 


I.  Rhythm. 


Imaginary 
rhythm. 


So  much,  then,  for  the  more  important  of  the 
lowest  sensory  materials  of  art.  We  must  now  pass 
over  to  the  other  side  just  mentioned,  to  the  xwdA.- 
ment3.ry  forms  that  we  find  agreeable,  more  particu- 
larly to  the  space-forms,  composed  of  line  and  sur- 
face, and  to  the  time-forms,  such  as  the  rhythm  of 
verse  and  of  music. 

It  is  curious  to  note  the  craving  of  the  mind  for 
form  of  some  kind;  so  that  we  are  never  satisfied 
with  separate  unorganized  impressions.  The  multi- 
tude of  stars,  for  instance,  are  not  left  as  disconnected 
points  of  light,  but  are  soon  grouped  by  us  into  con- 
stellations marked  off  by  imaginary  boundaries.  In 
this  way  they  become  mentally  more  friendly  and 
manageable.  The  very  same  thing  goes  on  in  the 
totally  different  region  of  sound.  I  have  already 
referred  to  the  fact  that  a  succession  of  sounds  of  the 
same  general  kind  will  almost  inevitably  be  broken 
up  mentally  into  groups,  and  that  each  group  has  a 
certain  organization,  some  of  its  members  being 
subordinate,  while  others  are  brought  to  the  front. 
If  the  sequence  of  sounds  is  reasonably  uniform  and 
monotonous,  as  with  the  metronome  or  the  regular 
throbbing  of  a  steam-engine,  the  sounds  (as  has 
already  been  brought  out)  ^  soon  take  on  a  fanciful 
rhythm,  and  each  measure  or  **  bar  "  of  the  rhythm 


now  the  other,  but  neither  of  these  limits  can  it  actually  reach.  The 
two  are  thus  necessary  and  inseparable  aspects  of  all  reality,  whose 
mutual  proportions,  however,  may  vary  indefinitely  (like  the  two 
abstractions,  surface  and  volume,  of  things  physical),  but  never  to  the 
exclusion  of  either  one  of  the  pair. 
1  Vide  p.  99. 


The  Enjoyment  of  Sensations  233 

has  a  duration  corresponding  to  what  we  might  call 
the  normal  pulse  of  consciousness,  which  lasts  not  far 
from  I  to  1.5  seconds.  If  a  measure  in  this  monoto-  Rate  of 
nous  material  is  to  be  pleasing,  it  must  take  up  about  rhythm* 
this  same  absolute  time  of  i  to  1.5  seconds,  no  matter 
how  many  separate  sounds  it  may  contain.^  A  meas- 
ure is  a  group  of  elements  that  can  be  held  in  a  single 
span  of  attention ;  so  that  for  a  rhythm  to  be  agreeable 
it  must  rise  and  fall  at  the  rate  at  which  this  inner 
process  of  attention  can  easily  go  on.  If  a  measure 
lasts  too  long,  it  is  felt  as  a  strain  upon  the  attention ; 
if  it  is  too  rapid,  it  seems  restless  and  we  weary  in 
trying  to  keep  pace  with  it. 

At  first  sight  it  is  not  easy  to  reconcile  these  re-  But  the 
suits  with  the  actual  facts  of  versification  and  music,  pol^t^^ought 

If  one  repeat  —  then  to  seem 

unpleasantly 

"  Heard  melodies  are  sweet,  but  those  unheard  rapid. 

Are  sweeter ;  therefore,  ye  soft  pipes,  play  on  ; 

Not  to  the  sensual  ear,  but,  more  endear'd. 

Pipe  to  the  spirit  ditties  of  no  tone." 

it  will  be  found  that  this  takes,  perhaps,  about  twelve 
seconds,  and  in  this  time  we  have  covered  twenty 
feet,  or  measures,  according  to  the  ordinary  scansion. 
This  would  give  less  than  two-thirds  of  a  second  for 
each  foot,  —  in  verse,  too,  which  strikes  us  not  as 
rapid,  but  as  rather  the  reverse.  If  in  the  psychologi- 
cal rhythm,  as  it  might  be  called,  —  the  natural  pulse 
of  attention,  spoken  of  above  —  the  measure  is  a  little 
over  one  second,  it  would  seem  that  verses  like  these 
should  strike  us  as  hurried  rather  than  as  deliberate. 

1  Bolton,  American  Journal  of  Psychology  ^  Vol.  VI,  p.  145. 


234 


Experimental  Psychology 


The  psy- 
chological 
measure 
is  distinct 
from  the 
metrical 
"foot." 


Poetic 
rhythm  then 
fits  the  labo- 
ratory time. 


The  fact  is,  that  the  real  mental  measure  in  these 
verses  does  not  coincide  with  the  ordinary  pentameter 
scansion  at  all,  but  proceeds  in  more  deliberate 
fashion,  having  its  divisions  something  like  this, 
where  the  full  lines  show  the  points  of  more  marked 
psychological  division,  the  dotted  lines  the  less  de- 
cided boundaries :  — 

"  Heard  melodies  are  sweet,  |  but  those  unheard  j 
Are  sweeter ;  |  therefore,  ye  soft  pipes,  :  play  on ;  | 
Not  to  the  sensual  ear,  |  but,  more  endear'd,  j 
Pipe  to  the  spirit  :  ditties  of  no  tone."  | 

Here  are  nine  measures,  and,  when  read  as  before, 
over  a  second  would  fall  to  each.   And  thus  the  time 
of  these  important  features  of  the  rhythm  corresponds 
fairly  well  with  the  wave-rate  of  attention. 
So,  too,  in  the  verses :  — 

"  She  dwells  with  Beauty  —  Beauty  that  must  die  ; 

And  joy,  whose  hand  is  ever  at  his  lips 
Bidding  adieu  ;  and  aching  Pleasure  nigh, 

Turning  to  poison  while  the  bee-mouth  sips  : 
Ay,  in  the  very  temple  of  Delight 

Veil'd  Melancholy  has  her  sovran  shrine." 

We  read  them  in  perhaps  seventeen  seconds,  and 
since  there  are  six  pentameter  lines,  there  would  be 
about  a  third  of  a  second  for  each  of  the  thirty  feet  if 
we  assumed  that  there  are  as  many  mental  pulses  as 
there  are  verse-feet.  But  there  are  really  not  more 
than  about  twelve  mental  measures  in  these  lines,  so 
that  each  psychic  foot  has  nearly  a  second  and  a  half 
—  a  deliberate,  unhurried  rhythm.^ 

1  Some  time  ago  my  colleagues,  Dr.  Noble  and  Mr.  Hart  (the  latter 
now  at  Harvard  University),  kindly  consented  to  make  a  wider  range 
of  measurements  than  those  which  I  had  made  upon  myself,  and  of 


The  Enjoyment  of  Sensations  235 


In  more  rapid  verse,  like  — 

"  Shakespeare  was  of  us,  Milton  was  for  us, 

Burns,  Shelley,  were  with  us,  —  they  watch  from  their  graves! 
He  alone  breaks  from  the  van  and  the  freemen. 
He  alone  sinks  to  the  rear  and  the  slaves! " 

which  takes  about  twelve  seconds,  we  have  sixteen 
feet,  according  to  strict  metrical  arrangement;  yet 
there  are  only  eight  or  ten  points  on  which  there 
is  any  real  mental  stress.  These  it  would  seem  are 
the  real  units,  and  the  scansion  feet  are  but  ripples 
on  the  larger  waves.  So  that  the  length  of  each  psy- 
chological measure  here,  too,  is  a  little  over  a  second 
on  the  average,  and  consequently  not  far  from  the 
pulse  time  of  attention  as  the  laboratory  experiments 
determine  it.  In  music,  also,  in  all  probability,  a  The  same 
somewhat  similar  agreement  would  be  found,  if  we  ^°^5^Jf 

°  ^  probably  ap- 

measure,  not  by  the  artificial  bar  divisions,  but  by  the  plies  to 
actual  stretches  of  mental  interest — the  "phrases"  "^^^^^• 
(or  in  the  slower  Choral  music,  even  the  single  notes), 
which  are  the  more  natural  units  that  give  the  compo- 

which  examples  are  given  in  the  text.  "With  quite  a  variety  of  com- 
position (verse  and  prose)  they  found  a  fairly  constant  rate  of  psycho- 
logical measure  for  each  of  their  three  subjects,  whatever  the  form  of 
composition  might  be,  although  among  the  subjects  themselves  there 
was  considerable  variation.     In  summary  they  found :  — 


Subject 

H. 

N. 

A. 

Average  time  of  a  single  measure, 

in  seconds 
Mean  variation  (per  cent) 

1.73 
14. 

1.22 
6. 

I.4S 
12. 

For  all  three  subjects  the  average  measure  was  thus  1.47  sec,  and  the 
average  variation  1 1  per  cent. 


236  Experimental  Psychology 

sition  its  psychological  rhythm.  The  satisfaction 
which  rhythm  gives  is,  at  least  in  part,  due,  then,  to 
the  existence  of  a  natural  pulsation  in  our  mental  life, 
and  the  rate  of  this  psychic  pulse  roughly  determines 
the  rate  at  which  pleasing  rhythm  may  occur  in  art.^ 

1  Since  the  above  was  written,  there  has  appeared  the  elaborate 
phonographic  research  by  Mr.  J.  E.  Wallace  Wallin  on  the  "  Rhythm 
of  Speech,"  in  the  Studies  from  the  Yale  Psychological  Laboratory, 
Vol.  IX  (1901).  Mr.  Wallin,  too,  finds  a  certain  approximation  be- 
tween some  of  the  larger  rhythms  of  speech  (especially  of  poetry)  and 
the  normal  attention-rhythm.  But  the  rhythm  on  which  he  lays  most 
stress  has  as  its  unit  the  verse^  or  line  (average  duration  2.69  sec;  but 
where  the  rhythmic  effect  is  most  marked,  average  1.67  sec,  —  these 
being  in  each  case  the  net  time,  i.e.  the  time  left  after  subtracting 
the  pauses  between  lines).  This  1.67  sec.  verse-group,  he  feels,  tallies 
fairly  well  with  the  normal  attention-time.  Less  important  for  him  is 
the  shorter  unit,  called  an  "  expiration  group,"  and  marked  off  by 
breathing  pauses  which  do  not  necessarily  correspond  with  the  termi- 
nation of  a  line.  This  unit  he  finds  on  the  average  to  be  of  1.19  sec. 
duration  (again  omitting  the  silent  time  between  the  units)  and  shorter 
than  the  psychological  rhythm,  and  therefore  difficult  to  identify  with  it. 

It  seems  to  me  that  in  this  "  expiration  group,"  rather  than  in  the 
"verse-group,"  Mr.  Wallin  is  closest  to  the  psychological  heart  of  the 
matter.  But  even  here  we  have  not  as  yet  the  real  basis  of  the  mental 
measure,  as  I  conceive  it,  but  only  one  element  in  it.  The  silent 
interval  between  his  ^^ groups''^  (average  0.44  sec,  as  Mr.  Wallin  gives 
it)  seems  to  me  an  integral  part  of  the  rhythm,  corresponding  to  the 
trough  of  the  psychological  wave;  and  were  this  added,  we  should 
have  a  time  (average  1.63  sec.)  which  is  not  far  from  the  attention- 
pulse  as  we  know  it.  The  most  significant  thing  in  comparing  the 
rate  of  verse-rhythm  with  the  attention-rhythm  is  the  time  from  crest 
to  crest  in  each  case,  and  not  simply  the  average  duration  of  the  crests 
themselves,  as  in  Mr.  Wallin's  "  groups."  With  this  change  of  inter- 
pretation, Mr.  Wallin's  results,  I  feel,  are  quite  in  support  of  the  view 
offered  in  the  text.  His  "  expiration  group,"  plus  the  silent  interval, 
would  correspond  to  my  "  psychological  divisions  of  the  verse,"  and  his 
measurements  (with  this  correction)  are  roughly  in  accord  with  what  I 
there  give,  and  are  undoubtedly  much  more  accurate  and  reliable. 


The  Enjoyment  of  Sensations  237 

In  contrast  with  the  pleasure  of  rhythm  which  is  2.  Pleasure 
present  in  poetry,  in  music,  and  in  the  dance,  there  ^"rln^e^-" 
is  the  gratification  which  comes  from  space-arrange-  ments: 
ments.     The  satisfaction  which  we  take  in  a  beautiful  simple  Une 
curve,  or  even  in  a  delicately  drawn  straight  line,  has 
by  many  been  supposed  to  be  not  a  pleasure  in  the 
form  itself,  but  in  the  quality  of  the  sensations  which 
accompany  our  perception  of  the  form.     The  eye,  in 
following  a  graceful  curve,  these  theorists  hold,  has 
an  ease  of  movement,  an  enjoyable  muscular  activity, 
which  an  irregularly  broken  line  does  not  give.     The  The  muscu- 
muscular  sensations  are  here  supposed  to  be  the  pleas-  Iheo^^^*'°" 
ant  thing,  while  the  form  itself  is  not  enjoyable  ex- 
cept indirectly  as  a  stimulus   to   pleasant   muscular 
feelings.     This  view,  of  course,  would  reduce  the  en- 
joyment of  form  to  a  sensuous  pleasure,  to  a  pleas- 
ure in  the  bare  muscular  sensations  which  enter  into 
the  experience,  rather  than  to  an  enjoyment  of  the 
real  form  of  the  impression. 

It  seems  to  me  that  the  satisfaction  which  we  take  Evidence 
in  Hnes  is  not  to  be  so  easily  explained.     Mere  ease  ^^^J^g^^^  L"" 
of  movement  of  the  eye  —  the  muscular  sensation  it-  not  from  the 
self  —  is  perhaps  a  factor  in  the  pleasure,  but  a  sub-  ^y^-^^^cies. 
ordinate  factor  at  best.     In  the  first  place,  the  move- 
ments of  the  eye,  unless  they  become  of  considerable 
range  or  rapidity,  are  scarcely  noticed  at  all,  as  can 
be  readily  shown  by  watching  a  single  dim  reflection 
of  Hght  on  the  wall  of  a  dark  room.     Even  when  this 
light  is  motionless,  it  will  often  seem  to  move,  since 
the  movements  of  our  eyes  unnoticed  by  us  are  taken 
to  be  movements  of  the  light.     If  we  were  so  sensi- 
tive to  muscular  changes  in  the  eye  as  some  believe. 


238  Experimental  Psychology 

we  should  attribute  the  movement,  not  to  the  light, 
but  to  our  eyes.  In  the  second  place,  if  we  close  our 
eyes  and  roll  them,  the  movements  they  make,  easy 
though  they  be,  are  either  absolutely  pleasureless  or 
are  infinitely  less  satisfactory  than  the  artistic  lines 
we  so  much  enjoy.  And,  finally,  if  we  watch  the 
actual  movements  which  another's  eye  makes  as  he 
looks  at  a  line,  say,  like  that  in  Fig.  46,  it  will  be 

at  once  noticed 
that  his  eye  it- 
self makes  no 
easy  and  grace- 

F1G.46.  ^"^     ^^^  ^^^^P  ^l^^S 

the  contour,  but 

moves  in  a  rapid,  jerky  course  from  point  to  point. 

Photographic  A  mcchanical  record  of  the  path  the  eye  takes  in 

re-Tbe^^*^^  looking  at  such  a  curve  has  an  unexpected  appear- 

havior.  aucc.     A  Sample  of  such  a  record  is  given  in  Fig.  47, 

obtained  by  placing  a  camera  so  that  it  would  catch 

the  tiny  image  of  an  arc-light  mirrored  in  the  front 

surface  (the  cornea)  of  the  eye  as  an  observer  swept 

his  glance  along  the  curve  shown  in  Fig.  46.     The 

heavier   dots    of    the   record   show   the   momentary 

pauses  in  the  eye's  motion,  the 

lighter  lines  giving  its  course 

as  it  leaped  from  point  to  point.       FIG.47.- Characteristic  rec 

It    is    thus    seen    that    the    eye  ©rd  of  the  eye's  path  in 

•  tj  •     •         ii_  following    the    curve    in 

runs  a  wild  course,  missmg  the  pig.  46.  from  left  to  right. 
line,  darting  back  on  it  again, 

moving  now  in  straight  Hues,  and  now  in  curves  even 
more  complicated  than  the  line  it  is  telling  us  of. 
The  eye's  own  motion  is  therefore  entirely  different 


The  Enjoyment  of  Sensations  239 

from  the  form  it  reports.     If  we  substitute  for  the 
curve  in  Fig.  46  an  ugly  variant  (Fig.  48),  the  path 
taken  by  the  eye  is  not  enough  different  to  account 
for    the   differ- 
ence of  our  feel- 
ing towards  the 
Hne    (see    Fig. 
49);  all  of  which  ^      ^     ^       ,       .    .  rr.-     ^ 

^  ^  ^ '  ,  Fig.  48. — An  ugly  variant  of  Fig.  46. 

goes    to    show 

that  the  muscular-sensation  theory  of  linear  grace  is  • 
utterly  untenable.     Our  aesthetic  feeling  toward  vis- 
ual forms  cannot  be  explained  as  an  appreciation  of 
the  muscular  sensations  which  such  forms  arouse.^ 

Why  a  particular  form  of  line  should  be  pleasing,  is  why  we  en- 
doubtless  due  to  a  combination  of  factors,  —  to  a  curi-  j°feg^^*^^^ 
ous  mixture  of  pleasurable  feehngs  connected  with 
intellectual,  sympathetic,  and  volitional  processes.  In 
the  first  place  a  regular  line  is  more  easily  grasped, 
requires  less  effort  of  attention. 
Its  course  throughout  is  in 
keeping  with  what  any  limited 

Fig.  49. —  Characteristic  rec-  .  .    ^.        ,. 

ord  of  the  eye's  path  in     portion    of    the     hne    SUggCStS, 

following  the  curve   in    and   thus   the  mental  process 
^^*  '^^'  of   conceiving    or    of    under- 

standing the  character  of  the  line  is  easier  and 
more  agreeable.  If  there  is  some  surprise  as  we 
pass  along  a  graceful  line,  it  is  not  a  violent  sur- 
prise, not  a  shock.  The  ugly  line,  however,  does 
not  follow  any  simple  law;   the  sight   of   a   single 

1  A  fuller  account  and  discussion  of  these  experiments  and  their 
results  appears  in  my  contribution  to  the  Wundt  Festschrift,  Leipzig, 
1902,  Vol.  II,  p.  336. 


240  Experimental  Psychology 

portion  does  not  give  us  the  key  to  the  whole ;  and 
for  this  reason  it  does  not  appear  to  hold  together. 
Its  different  parts  require  special  and  disconnected 
processes  of  attention,  and  so  the  whole  gives  an 
impression  of  strain  and  lawlessness.  But  besides 
the  greater  ease  in  mentally  grasping  a  graceful 
line  because  its  parts  can  be  brought  under  some 
single  law  or  formula,  its  character  is  such  as 
to  call  out  a  kind  of  sympathy  that  no  ugly  Hne 
invites.  Graceful  lines  are  by  experience  often 
found  to  be  the  expression  of  movements  that 
are  under  perfect  control,  or  in  which  there  is  no 
suggestion  of  insuperable  checks  and  hindrances. 
The  evolutions  of  the  skater,  the  flight  of  birds, 
the  movements  of  a  hand  so  trained  that  it  abso- 
lutely obeys  the  will,  give  us  impressions  of  this 
character.  So  that  the  lines  that  please  us  are 
those  that  suggest,  though  perhaps  very  dimly,  a 
life  that  is  master  of  the  situation.  Such  life  we 
sympathize  with;  it  is,  in  a  way,  what  we  are  all 
striving  to  attain ;  we  dislike  anything  that  sug- 
gests defeat  or  failure  to  cope  with  circumstances. 
And  what  we  sympathize  with  we  imitate.  We 
often  feel  ourselves  vaguely  participating  in  the 
movement  suggested  by  pleasing  curves ;  we  go 
through  them  ourselves,  making  at  least  incipient 
movements  like  those  represented  in  the  line.  The 
imitative  participation  in  what  we  already  take 
pleasure  in  of  course  heightens  the  pleasure,  while 
a  similar  participation  in  movements  that  are  unat- 
tractive increases  the  disagreeable  impression.  The 
pleasurable  imitation,  the  associations  that  make  us 


The  Enjoyment  of  Sensations  241 

sympathetic  with  what  a  graceful  Hne  suggests,  the 
lessened  tax  such  lines  make  upon  the  attention  — 
so  much,  at  least,  enters  into  our  enjoyment  even 
of  these  simple  forms.  Our  pleasure  consequently 
does  not  come  from  mere  muscular  ease  or  the 
absence  of  sensuous  fatigue  in  the  eyes. 

We  may  now  pass  from  the  beauty  of  the  single  b.  Combina-      \ 
line  to  the  satisfaction  we  take  in  the  arrangement  *^°"s  °^  ^^"^s-     ■ 
of  two  or  more  lines,  —  in  harmony  and  proportion. 
The  chief  result  of  the  experimental  investigations  in 
this  region  has  been  to  reveal  the  presence  of  peculiar  1 

mathematical  relations  in  those  combinations  which  \ 

are  most  agreeable.     Figures  like  the  square  or  circle,  I 

which  show  equality  of  dimensions,  give  us  a  mild  Symmetry.        | 
satisfaction  because  of  their  very  regularity.    They  are  I 

special  and  extreme  cases  of  that  symmetry  to  which,  |j 

in  spite  of  occasional  coolness,  we  all  have  a  deep-  j 

seated  attachment.     Our  fondness  for  symmetry,  ex-  \ 

cept  when  it  is  overdone  and  rouses  us  to  rebellion,  is 
probably  not  unlike  our  satisfaction  in  graceful  lines : 
we  like  its  orderHness,  its  intelligibility,  while  at  the 
same  time  it  offers  always  a  variation  of  its  theme,  in 
that  the  one  half  repeats  and  yet  reverses  the  arrange- 
ment of  the  other.  Its  very  likeness  in  this  respect  Eye-move- 
to  the  regularity  and  variation  in  the  single  Hne  has  "^^"*  ^^^°^ 
tempted  men,  more  and  more,  to  explain  its  attractive- 
ness in  a  similar  way,  as  due  to  the  character  of  the 
eye-movements  which  it  evokes,  although  in  the  case 
of  symmetry  such  theories  lay  less  stress  on  the  mere 
ease,  and  more  on  the  balance  of  movements,  or  on 
the  repose  of  the  eye  which  symmetrical  arrange- 
ments induce. 


2^2  '    Experimental  Psychology 


But  the  reasons  already  given  seem  to  make  such 
a  theory  quite  unconvincing.  And,  moreover,  direct 
experiments  indicate  that  symmetrical  figures  do  not, 
to  any  appreciable  extent,  invite  the 
eye  to  rest,  or  to  balance  of  move- 
ment. Figure  50  is  a  copy  of  a  photo- 
graphic record  taken  in  the  way  de- 
scribed on  page  238.  An  outline  like 
that  in  Fig.  51  was  placed  before  an 
observer,  with  instructions  to  look  at 
the  figure  in  a  natural  way,  nothing 
of  course  being  said  in  this  case 
about  following  the  line.  No  "bal- 
ance" of  eye-movements  is  evident. 
The  eye  roves  quite  irregularly  over 
such  a  figure,  and  yet,  in  spite  of 
the  way- 
wardness 
of  these 
organic 
motions,  the  absolute  reg- 
ularity of  the  external 
form  itself  is  fully  felt. 
The  eye-movement  theory 
here  again  finds  no  sup- 
port in  the  facts.  The 
satisfaction,  as  in  the  case 
of  single  lines,  does  not 
lie  in  the  muscular  sensa- 
tions aroused,  but  in  our 
appreciation  of  the  character  of  the  form  itself.  It 
is  a  pleasure  of  form,  and  not  of  sense  merely. 


Fig.  50.  — Record 
of  the  eye's 
course  in  look- 
ing at  Fig.  51 
freely  with  no 
attempt  to  fol- 
low the  outline. 
B  is  the  begin- 
ning, E  the  end 
of  the  record. 


Fig.  si. 


The  Enjoyment  of  Sensations  243 

But  passing  from  symmetry  with  its  equality  of  Pleasure  and 
parts,  distinct   mathematical   proportions  are  found  ^fj'atios!^' 
imbedded  in  other  experiences  which  give  us  aesthetic 
pleasure.     The   musical  tones,   for   instance,  which  Musical  har- 
make  a  harmonious  union  are  those  which  stand  to  ™°"^* 
each  other  in  a  very  simple  arithmetical  ratio.     In 
the  harmony  of  the  octave,  the  upper  tone  has  twice 
the  number  of  vibrations  of  the  lower;  in  the  har- 
monious  interval   of    the    fifth   {c-g\   the   ratio   of 
vibrations  of  the  two  tones  is  as  2:3;  in  the  fourth 
{c-f)  the  relation  is  that  of  3:4;  in  the  third  {c-e)y 
4:5,  and  so  on;  while  the  more  complicated  ratios, 
as  that  of  12:13,  affect  us  as  discords. 

No  such  law  has  been  found  in  the  case  of  pairs  Color 
of  colors  which  harmonize.  Colors  have  their  rates  ^^^™°"y- 
of  vibration;  but  some  colors  whose  rates  would 
make  as  simple  a  mathematical  ratio  as  appears  in 
musical  harmonies,  are  distinctly  antagonistic,  while 
other  combinations  whose  ratios  of  vibration  would 
correspond  to  a  musical  discord  give  a  pleasing 
effect.1 

But  in  space-forms,  a  study  of  the  combinations  of  Proportion 
lines  which  seem  to  be  in  due  proportion  shows  that  °^  ^^"®^* 
here,  also,  there  is  an   approach   to  a  simple  arith- 
metical relation.     The  most  remarkable  instance  of 
this  kind  is  found  in  our  preference  for  particular  The  "gold- 
proportions  in  rectangles.     An  aesthetic  tendency,  of 
this  kind,  having  a  fairly  constant  character,  is  shown 
in  the  general  shape  of  book-pages,  panels,  pictures, 
and  the  like.     Fechner  and  others  have  found  that 
on  the  average  the  preferences  of  people  fall  near 

1  Cf.  Helmholtz,  Physiologische  Optik,  2d  ed.,  pp.  399  et  seq. 


244 


Experimental  Psychology 


.AUeged 
delight  in 
mathematics. 


Fig.  52.  —  Rectangle  whose 
sides  have  the  proportion 
knovm  as  the  "golden 
section"  (i:i.6i8+). 


that  rectangle  whose  shorter  side  is  to  the  longer 
as  this  longer  is  to  the  sum  of  the  two  —  a  figure 
that  can  be  constructed  by  making  the  two  sides 
in  the  proportion  of  i  to  1. 61 8,  or  roughly,  of  5  to  8 
(Fig.  52),  a  ratio  now  generally  known  as  the  "  golden 
section."  Experiments,  moreover,  on  a  wide  variety 
of  space-arrangements  where 
the  feeling  of  proportion  en- 
ters,—  in  merely  dividing  a 
perpendicular  line,  for  in- 
stance, so  that  the  two  parts 
shall  seem  in  harmony ;  or  in 
selecting  from  ellipses  whose 
axes  are  of  different  relative 
lengths  the  one  most  pleasing, 
—  in  all  such  cases  there  is  found  to  be  an  astonishing 
partiality,  not  invariably  for  the  golden  section,  it  is 
true,  but  for  a  ratio  somewhere  in  its  neighborhood. 
The  Roman  cross  shows  the  force  of  this  feeling  of 
proportion ;  the  cross-bar  here  has,  for  aesthetic  rea- 
sons, been  lowered  decidedly  from  its  position  in  the 
actual  instrument  of  execution.  In  general,  if  there 
is  free  choice,  we  prefer  not  to  have  actual  equality 
of  the  main  dimensions,  such  as  appears  in  the  square 
or  circle  or  the  Greek  cross. 

Those  with  strong  mathematical  proclivities  have 
tried  to  explain  these  results  as  due  to  some  secret 
enjoyment  coming  from  the  mathematical  instinct. 
The  attractiveness  of  a  figure  which  shows  the 
golden  proportion,  according  to  this  view,  consists 
not  in  its  immediate  space-appearance,  but  rather 
in  the  peculiar  arithmetical  formula  which  the  figure 


The  Enjoyment  of  Sensations  245 

emb6dies.  A  similar  theory  would  explain  our  satis- 
faction in  musical  harmony  as  likewise  a  gratification 
of  our  mathematical  sense ;  we,  so  to  speak,  subcon- 
sciously count  the  vibrations  and  notice  that  they 
stand  in  a  simple  and  pleasant  numerical  relation. 

But  if  we  accept  this  hypothesis,  it  would  be  diffi-  Fickleness  of 
cult  to  see  why  a  certain  mathematical  idea  should  Jjjatka??aste 
be  so  gratifying  when  embodied  in  visual  material, 
and  yet  not  be  especially  attractive  when  given  in 
the  form  of  sound.  Thus  the  golden  ratio,  that 
pleases  us  in  the  rectangle,  is  by  no  means  the  most 
satisfactory  when  incorporated  in  musical  tones. 
Two  tones,  one  of  128  vibrations  and  the  other  of 
207  vibrations,  (the  golden  ratio),  strike  us  as  at 
least  a  somewhat  strained  harmony.  And  even  if  we 
were  to  suppose  that  in  the  perception  of  tones  we 
were  subconsciously  aware  of  their  vibrations,  would 
it  not  be  quite  as  difficult  to  account  for  our  decided 
preference  for  a  ratio  such  as  that  of  4  to  5,  which 
is  a  musical  harmony,  as  against  the  ratio  of  10  to  11, 
which  is  musically  discordant  ?  As  a  bare  mathemat- 
ical ratio,  10  to  11  is  as  good  as  any,  and  yet  when 
embodied  visually  or  in  auditory  material  it  would 
not  be  received  by  many  of  us  with  marked  favor. 
And  if  further  evidence  were  needed  that  the  mere 
incorporation  of  certain  arithmetical  ratios  is  not  of 
itself  attractive,  it  could  be  found  by  experimenting 
on  divisions  of  time  according  to  the  proportions 
which  please  in  other  fields.  If  we  mark  off  two 
stretches  of  time  so  as  to  make  the  proportion  of 
5  to  8,  which  pleases  us  in  the  rectangle,  or  the  pro- 
portion of  4  to  5,  which  satisfies  us  in  pitch,  we  find 


246 


Experimental  Psychology 


that  these  temporal  realizations  of  the  mathematical 
idea  leave  us  aesthetically  unmoved. 

From  these  instances  I  think  we  may  be  justified 
in  the  generalization  that  the  soul  is  not  particularly 
responsive  to  simple  mathematical  ratios  as  such. 
The  theory  itself  is  a  curious  bit  of  mysticism  —  a 
remnant  of  the  old  Pythagorean  philosophy  of  num- 
ber. But  certainly  it  is  impossible  to  believe  that 
the  numbers  per  se  are  pleasant  when  they  are  agree- 
able to  us  as  exemplified  in  space,  but  not  when  pre- 
sented in  time,  or  when  one  set  of  numbers  pleases 
us  in  sound  and  an  entirely  different  set  in  color. 

It  is  easier  to  find  what  is  not  the  explanation  of 
our  choice  of  combinations  of  tones  or  colors  or  lines 
than  to  discover  what  the  cause  actually  is. 

It  is  probable  that  in  these  different  cases  differ- 
ent factors  are  at  work.  As  for  musical  harmony, 
and  for  color  harmony  in  so  far  as  we  have  in  mind 
simply  the  agreeableness  of  complementary  hues 
like  purplish  red  and  green,  for  instance,  or  blue  and 
yellow,  their  explanation  apparently  lies  mainly  in 
our  physiological  constitution.  The  concordant  notes 
or  colors  produce  no  nervous  rasping  or  friction  ;  the 
one  restores  the  organ  which  has  been  wearied  by  the 
other;  they  give  us,  as  Mr.  Grant  Allen  expressed 
it,  a  maximum  of  stimulation  with  a  minimum  of 
fatigue.  But  when  we  turn  to  those  beautiful  com- 
binations of  colors  that  are  near  akin  —  the  similar 
but  slightly  contrasting  tints  of  yellow  in  the  daf- 
fodil, or  those  varied  harmonies  of  brown  in  the 
late  summer  landscape  of  CaHfornia  —  I  doubt  if  the 
nervous  resources  of   the  eye   itself   are   much  less 


The  Enjoyment  of  Sensations  247 

taxed  in  viewing  these  than  if  there  were  an  absolute 
monotony  of  tone.  The  refreshment  which  the  sHght 
departure  from  the  dominant  note  here  affords  is 
not  so  much  a  refreshment  to  the  physical  as  to  the 
mental  eye.  The  comparison  of  the  hues  and  the 
appreciation  of  their  similarity,  as  well  as  of  their 
contrast,  gives  us  pleasure ;  the  recognition  of  their 
veiled  differences  adds  to  the  pleasure  we  receive  in 
the  terms  themselves.  Something  of  this  kind  prob- 
ably is  also  present  in  those  figures  which  preserve 
the  golden  ratio :  the  golden  section  is  a  golden 
mean  between  monotony  and  violent  contrast.  A 
happy  balance  is  somehow  struck  between  too  little 
variety  and  too  much.  But  why  the  balance  should 
be  struck  at  the  particular  point  which  the  experi- 
ments show,  no  one  is  yet  in  a  position  to  say. 

The  chief  result  of    these  various    experimental  Ourenjoy- 
studies  is,  consequently,  to  bring  out  the  truth  that  our  J"^"*  '^ 
enjoyment  even  of  the  rudiments  of  beauty  comes  sources, 
from  many  sources,  and  that  it  is  impossible  to  adopt 
a  single  principle  which  will  apply  to  every  case.     It 
is  impossible  to  say  that  all  our  aesthetic  pleasures 
can  be  reduced  to  sensuous  enjoyment.     Some  of  the  \ 
pleasure  certainly  is  an  enjoyment  of  the  sensations 
themselves ;  the  note  of  the  linnet,  or  the  pure  blue 
of  the  sky,  is  good  as  mere  sensation ;  but  over  and 
above  this  there  is  a  pleasure  in  the  arrangement  or 
form  of  the  sensations,   and  in  the  sympathies  and 
reactions  which  such  forms  call  forth  either  directly 
or  by  force  of   association.     And   yet  we  must  not 
so  emphasize  our  enjoyment  of   form  as  altogether 


248 


Experimental  Psychology- 


Higher 

and  lower 
are  inter- 
mingled 
throughout. 


to  deny  the  existence  of  a  pleasure  of  sense.  Again, 
the  principle  of  unity  in  variety,  to  which  writers  on 
aesthetics  are  ever  recurring,  is  undoubtedly  im- 
portant, as  we  found  in  the  case  of  symmetry  and 
of  all  those  proportions  which  strike  us  pleasantly ; 
but  alone  and  of  itself  it  will  explain  nothing. 
Unity  in  variety  per  se  is  absolutely  indifferent  and 
unaesthetic;  a  government  letter-box  has  a  kind  of 
unity  in  variety  quite  as  truly  as  a  Greek  vase ;  and 
a  railway  time-table,  as  truly  as  "  Lycidas " ;  but 
the  mere  embodiment  of  these  abstractions  does  not 
make  them  artistic.  In  any  real  work  of  art  we 
demand  that  there  shall  be  unity  in  variety,  but  we 
ask  for  much  besides.  So  that  the  psychological 
study  of  the  very  elements  of  art  shows  that  none 
of  these  principles  can  stand  alone.  At  the  very 
bottom,  even  in  what  we  regard  as  purely  sensuous 
enjoyment,  certain  higher  factors  are  bound  to 
enter ;  we  like  our  colors  or  our  sounds  to  be  com- 
plicated and  not  too  transparent;  we  like  them  to 
surprise  us ;  we  like  them  to  have  pleasing  associa- 
tions, or  to  be  imitative  of  colors  and  sounds  which 
we  know  and  can  recognize.  Thus,  the  tone  of  the 
violin  gains  much  by  its  likeness  to  the  human  voice ; 
while  the  faultless  note  of  the  tuning-fork  se^ms  un- 
natural; it  is  too  crystalline  and  unvocal.  And, 
on  the  other  hand,  even  in  the  highest  products  of 
art,  the  purely  sensuous  element  is  still  present. 
Understanding  and  sense,  form  and  matter,  are  in 
inseparable  company  throughout  the  entire  course. 


CHAPTER  XIII 

COLOR  AND  THE  DIFFERENTIATION  OF  THE 
FINE  ARTS 

The  sensuous  element  and  the  element  of  form  Sense  vs.  un- 
or  arrangement,  although  inseparable,  do  not  affect  ^^^^standing. 
all  persons  with  equal  force.  There  has  always  been 
more  or  less  partisanship  in  regard  to  the  two;  so 
that  theorists  as  well  as  artists  have  taken  sides  and 
have  emphasized,  now  the  bare  sense-impressions, 
and  now  those  aspects  of  things  which  appeal  more 
strongly  to  other  sides  of  our  minds.  Just  as  in  ques- 
tions of  philosophical  doctrine  there  have  been  from 
ancient  times  the  friends  of  sense,  or  of  matter,  like 
Democritus ;  and,  on  the  other  hand,  there  have  been 
those  like  Plato  and  St.  Paul,  who  felt  that  the  true 
life  was  mainly  apart  from  sense ;  —  so  in  art,  too,  the 
enmity  between  flesh  and  spirit  has  been  evident, 
and  although  perhaps  not  so  vehemently  argued  as  in 
former  times,  it  is  still  present  in  the  practice  of  to- 
day. Artistic  reactions  occur,  now  in  favor  of  form 
and  meaning,  while  again  the  desire  is  to  do  justice 
first  and  foremost  to  the  pleasure  of  eye  and  ear. 
Impressionism,  for  example,  is  such  a  reaction,  is  an 
attempt  to  give  its  full  due  to  the  brilliant  colors  of 
things,  regardless  of  whether  we  are  able  to  discern 
what  the  things  themselves   are   or   not,  and   often 

249 


250 


Experimental  Psychology 


The  opposi- 
tion of  color 
and  line. 


in  space- 
forms  is  the 
more  primi- 
tive. 


becoming  in  its  extremists  a  half-mad  revel  in  the 
immediate  impression,  bereft  of  form  and  intellectual 
order. 

Now,  so  far  as  the  opposition  is  simply  between 
drawing  and  color,  our  psychology  is  able  to  point  to 
several  facts  that  undoubtedly  have  a  bearing  on  the 
question.  There  is  good  evidence  that  the  sense  of 
color  is  of  later  psychological  development  than  the 
The  interest  sense  of  form.  Long  before  there  is  any  vision,  we 
have  a  muscular  and  tactual  apparatus  for  perceiving 
space-arrangements.  And  even  to  the  end,  our  color 
perception  is  so  unstable  and  easily  lost  that  we  can 
well  believe  that  the  feeling  for  form  is  more  deeply 
implanted  in  our  constitution  than  is  the  sense  of 
color.  It  may  not  be  true  that  all  children  are  color- 
blind during  the  earliest  months  of  infancy,  as  some 
believe ;  but  all  our  lives  there  is  a  considerable  por- 
tion of  the  field  of  view  where  we  are  either  totally 
color-blind  or  are,  at  most,  sensitive  to  color  only  of 
extreme  intensity.  If  small  colored  disks  be  brought 
into  the  margin  of  vision  so  that  we  do  not  look 
directly  at  them,  there  will  be  found  a  wide  zone  in 
which  we  can  see  the  shape  of  the  object  distinctly 
enough  but  not  its  color ;  the  color  does  not  appear 
until  the  object  is  brought  nearer  the  centre  of  sight. 
The  whole  of  vision,  consequently,  is  a  vision  of  form, 
while  only  a  part  of  it  makes  us  aware  of  color.^ 
The  number  of  persons  who  are  color-blind  even  in 


1  That  the  analogy  between  color-blindness  and  vision  with  the 
border  of  the  retina  must  not  be  pushed  too  far  is  shown  by  various 
recent  investigations;  see,  e.g.  Hellpach,  Philosophische  Studien,  Vol. 
XV,  p.  524,  and  Arnoult,  Revue  Philosophique,  Vol.  XLIV,  p.  1 10. 


Color  and  the  Fine  Arts  251 

the  very  centre  of  vision  and  yet  retain  the  power 
to  grasp  visually  the  shape  of  things,  shows  how 
relatively  ill-established  our  color  vision  is,  in  that 
it  can  so  readily  slip  away,  leaving  us,  as  some  have 
supposed,  in  our  ancestral  state  of  colorless  sight. 

Now,  whether  or  not  there  actually  be  a  widespread  Personal 
difference  in  the  purely  physical  endowment  of  men  r^^arTtV" 
whereby  some  are  sensitive  to  color  in  a  much  higher  color  and 
degree  than   others  whom  we   have   no  reason  to    °^"^* 
regard  as  color-blind,  there  certainly  is  a  widespread 
difference  with  regard  to   the  interest  in  the  color 
of  things,  as  compared  with  their  form.     It  may,  or 
may  not,  rest  on  an  actual  difference  in   our  eyes 
themselves.     Even  apart  from  any  such  difference.  Of  this  pair, 
the  interest  in  form  is  of  necessity  more  deep-seated  ^^°^  ^^  ™°'"® 
than  that  of  color;   it  is  less  a  luxury  and  more  a 
factor  that  is  indispensable  if  one   is   to   deal  with 
his  environment  and  live.     The  characteristic  marks 
of  things  by   which  we   recognize   them   and  treat 
them  as  friend  or  foe  are  given  in  their  form;  the 
color  is   relatively  unimportant.     How   much   more 
the  colorless  photograph  tells  —  of  scenery  and  of 
portraiture,  for  instance  —  than  any   possible   color 
chart,  which  should  never  so  faithfully  set  forth  in 
columns  the  tints  in  a  particular  landscape  or  in  a 
person's  face,  but  tell    nothing    of    the    form    and 
arrangement  of  these  colors.     For   this   reason,  we 
must  attend  to  the  shapes  of  things  or  die,  whereas 
an  interest  in  color  is  rarely,  if  ever,  forced  upon  us ; 
it  is  not  one  of  the  fundamentals. 

Now  in  this  regard,  while  most  persons  keep  well 
within  the  lines  of  common  utility  —  in  that  the  form 


252 


Experimental  Psychology- 


Colored 

sounds. 


Exaggerated    of  things  mtcrcsts  them,  but  not  unduly,  —  there  are 
development   ^^hers  whose  interest  takes  a  turn   that  is   as   yet 

in  each  of 

these  two  apparently  useless  and  inexplicable.  We  nave  one 
directions.  gj-Qup  made  up  of  persons  for  whom  color  has  in 
some  way  come  to  have  an  exaggerated  importance, 
while  there  are  others  in  whose  mental  life  spatial 
form  plays  an  abnormally  prominent  role.  Such  a 
division  seems  to  be  borne  out  by  certain  phenomena, 
noticed  in  recent  years,  which  show  in  many  indi- 
viduals a  curious  tenacity  for  pure  spatial  relations, 
so  that  all  things,  even  when  not  spatial,  are  persist- 
ently represented  as  having  this  form;  while  others 
think  of  things  preferably  in  terms  of  color,  although 
the  objects  themselves  may  be  colorless.  Some  per- 
sons represent  all  sounds  as  having  color;  an  ac- 
quaintance of  mine  thinks  of  the  higher  tones  of  the 
musical  scale  as  yellow,  while  the  lower  tones  have 
a  purplish  cast.  Such  persons  may  hear  all  words  as 
colored,  and  even  the  separate  elements  of  words 
have  their  separate  tinge.  In  the  word  "size,"  for 
example,  one  of  my  students  hears  the  opening  si  as 
yellow  passing  into  orange,  while  the  closing  z  sound 
is  distinctly  red.  Here  color  has  evidently  come 
to  the  mental  foreground  and  would  monopolize  the 
attention.  In  the  other  type  of  mind  everything  runs 
to  spatial  form.  All  ideas  here  have  their  spatial 
symbols :  —  in  a  case  I  know  of,  Wednesday  is 
always  represented  by  a  window  with  draped  cur- 
tains, while  Monday  is  thought  of  as  a  triangle 
with  a  dot  in  the  centre.  A  large  number  of  per- 
sons always  picture  the  common  series  —  the  months, 
the  alphabet,  the  number   series  —  as  arranged  in 


Space- 
thinking. 


1^ 


Fig.  53.  —  Wire  model  of  a  mental  number-form. 


Fig.  54.  —  Wire  model  ol  a  mental  number-form.     In  this  and  the  preceding 
figure,  the  vertical  supports  are  not  a  part  of  the  subjective  form. 


Color  and  the  Fine  Arts  253 

some  very  definite  shape,  often  exceedingly  intri- 
cate and  with  no  apparent  logical  appropriateness, 
but  yet  quite  constant  for  them  as  far  back  as 
their  memory  reaches.  The  accompanying  number- 
forms  (Fig.  53  and  54)  are  those  of  two  of  my  friends 
who  belong  to  this  type.  The  second  of  these  forms 
belongs  to  one  who  is  especially  interested  in  archi- 
tecture, which  would  be  additional  evidence  of  the 
role  that  spatial,  colorless  form  plays  in  his  mental 
world.  A  peculiarity  of  this  same  number-form  (to 
which  writers,  so  far  as  I  know,  have  made  no  refer- 
ence) is  that  with  the  higher  numbers  the  person 
changes  his  point  of  view,  apparently  turning  the 
form,  as  a  whole,  around,  and  looking  at  it  from  an 
opposite  side. 

But  while  it  might  be  questioned  whether  later  The  diver- 
investigation  will  show  that  there  is  the  significance  fnd^drawS^'^ 
here  conjectured  in  these  curious  tricks  of  mind,  mart, 
there  are  certainly  the  two  classes  of  men :  the  larger 
group  who  keep  to  the  great  underlying  interest  in 
form  —  the  interest  to  which  nature  herself  early 
trains  us ;  the  other  and  smaller  group  who  have 
developed  in  a  most  unpractical  way  a  peculiar  inter- 
est in  color.  This  difference  makes  us  understand 
better  the  different  excellences  of  artists,  as  well  as 
the  different  sympathies  which  the  laity  feel  with 
contrasting  schools  of  pictorial  art.  According  as 
the  chief  pleasure  is  taken  in  one  or  the  other 
side,  do  men  demand  that  the  drawing  or  the  col- 
oring of  a  picture  shall  not  be  deficient.  And  for 
a  like  reason,  there  are  artists  whose  strength  lies 
in  color,  like  Rubens  or  the  Venetians,  while  others 


54 


Experimental  Psychology 


frankly  turn  to  sculpture  or  line-work,  or  when  they 
use  pigments  they  find  their  chief  joy  in  producing 
effects  in  which  color  plays  a  less  essential  part,  and 
contrast  of  shadows  and  light,  or  the  modelling  of 
figures,  is  the  main  interest,  as  in  the  work  of  Rem- 
brandt or  the  frescos  of  Michelangelo. 


Rivalry  of 
the  sensuous 
and  the  inter- 
connective 
element. 


Nature 
forces  us  to 
subordinate 
one  or  the 
other  of 
these. 


But  if  the  opposition  between  color  and  pure  space- 
arrangement  as  shown  in  such  instances  as  these  were 
the  whole  story,  there  would  be  perhaps  some  little 
ground  for  the  feeling  already  referred  to  that  the 
sensuous  and  the  relational,  or  "formal,"  side  of  art 
are  in  conflict.  But  the  great  historic  doctrine  of  an 
opposition  and  even  an  antagonism  between  sense 
and  understanding  has  a  firmer  foundation  than  this. 
For  it  is  found  that  the  economy  of  the  mind  is  such 
that  if  the  sensuous  element  comes  into  prominence, 
it  does  so  at  a  certain  cost.  Great  vividness  of  sense- 
impressions  hinders  the  suggestiveness,  the  meaning, 
of  the  impressions ;  and,  on  the  other  hand,  our  grasp 
of  the  interconnection  of  things  —  the  play  of  under- 
standing over  and  around  an  object  —  takes  the  life 
from  the  sensations  which  the  object  gives.  So  that 
nature  herself  forces  a  choice  upon  us,  and  will  not 
give  unstintingly  of  both  at  once.  Thus  if  we  would 
see  in  any  object  its  pure  color  in  all  its  native  force, 
we  must  in  some  way  obscure  the  meaning  of  the 
color,  either  by  slightly  turning  the  head  or  by 
looking  at  a  broken  or  inverted  image  of  the  thing. 
Notice,  at  dinner,  what  fresh  pink  color  your  friends' 
faces  show  when  reflected  in  the  curved  surfaces  of 
the  silver ;  or  from  your  study-window  see  how  much 


Color  and  the  Fine  Arts  255 

more  violet  are  the  shadows  under  the  trees  when 
you  draw  your  curtains  and  see  the  landscape,  not 
as  foliage  and  earth  and  shade,  but  as  meaningless 
splashes  of  color  through  the  white  curtains  them- 
selves. And,  further,  we  can  never  appreciate  so 
well  the  subtler  relations  of  things  if  the  objects 
themselves  impress  our  senses  too  strongly.  If  we 
are  close  to  a  speaker  addressing  a  large  audience, 
the  mere  force  of  the  sound  hinders  our  thought; 
the  auditory  experience  is  so  prominent  that  the  full 
association,  the  significance,  of  his  words,  less  freely 
arises.  And  the  same  is  true  if  we  are  too  near  an 
orchestra ;  the  connection,  the  ^  unity  of  the  effect, 
is  lost  in  the  individual  sounds;  we  cannot  see  the 
forest  for  the  trees. 

It  is  because  of  this  general  law,  it  seems  to  me,  Poetry,  in 
that  all  poetry  as  it  becomes  more  serious,  suppresses,  ^^^^^gs^J^fg 
in    some    degree,   the    sensuous    auditory   element,  appeal  to 
Rhyme  or  recurrent  alliteration  are  felt  to   obtrude  *^^*^^'^- 
themselves  and  hinder  the  higher  functions  of  mind, 
as  do  also  too  obvious  metrical  effects.      Children's 
verses  can  stand  all  this;   it  is  suited  to  the  lyric 
temper.     But  in  general  the  more  thoughtful,  —  the 
more  spiritual, — the  mood,  the  less  it  can  tolerate  of 
mere   sensation.     It  is   true  there   are   troublesome 
exceptions,  like  the  terza  rima  of  Dante.      But  it  is 
perhaps  more  characteristic  that   Shakespeare  neg- 
lected his  rhymed  couplets  as  he  grew  older;  while 
in  the  poetry  of   Job  and   of   the  Psalms  the  more 
prominent  feature  is  neither  rhyme  nor  measure,  but 
rather  a  stately  form,  imperceptible  to  the  senses  — 
an  antithesis  or  repetition,  with  solemn  emphasis,  of 


256 


Experimental  Psychology- 


separation 

of  arts  so  that 
each  ele- 
ment may 
get  its  due. 


Instance  of 
the  auditory 
arts  of 
music  and 
poetry. 


the  thought  itself.  If  there  is  any  other  metrical 
arrangement,  it  is  so  obscure  that  its  very  existence 
is  still  in  dispute. 

But  this  does  not  mean  that  a  purified  art  will  of 
necessity  become  supersensuous ;  there  is  no  indica- 
tion that  art  as  a  whole  is  to  grow  more  austere.  So 
far  as  we  can  now  see,  the  tendency  is  rather  toward 
a  division  of  labor  —  toward  the  development  of 
special  arts  in  which  the  different  ways  of  appreciat- 
ing beauty  shall  each  be  recognized  without  slight : 
some  arts  in  which  the  sensibly  present  impressions 
shall  be  all  but  eliminated  and  the  enjoyment  con- 
nected with  the  ideas  they  arouse  shall  be  the  chief 
thing;  and  other  arts  in  which  the  mental  activity 
of  interrelating  the  parts  of  the  composition  is  subor- 
dinate and  the  sensory  pleasure  of  the  moment  can 
come  well  to  the  front.  Music  and  poetry  are  good 
instances  of  such  a  development  already  completed. 
In  primitive  life,  music  is  not  cultivated  as  of  value 
in  itself ;  it  is  subordinate  to  the  dance,  or  it  appears 
as  undistinguished  from  poetry  —  the  verses  are 
chanted  or  sung.  Music  is  here  but  a  handmaid  of 
other  arts.  But  men  finally  perceive  that  it  is  impos- 
sible to  do  full  justice  to  all  sides  at  once,  and  that  if 
the  ideas  of  poetry  are  so  excellent  as  to  engross  the 
attention,  the  mind  will  inevitably  neglect  the  sensu- 
ous clothing  of  the  thought,  —  the  music  of  the  verse ; 
and,  on  the  other  hand,  the  mere  musical  side  can 
satisfy  us  better  if  attention  is  not  demanded  for  other 
things.  Think  of  using  Hamlet  as  the  Hbretto  of  an 
opera !  The  opera  is  always  a  compromise ;  it  gives 
us  neither  the  highest  musical  nor  the  highest  dramatic 


Color  and  th 


257 


development. 


effect^  For  this  reason  music  finally  asserts  its  inde- 
pendence of  dancing  and  poetry,  and  is  cultivated  for 
its  own  sake.  The  modern  development  of  pure 
instrumental  music  thus  does  justice  to  the  sensuous 
side,  which  poetry  has  more  and  more  neglected. 
And  in  such  music  even  an  imitation  of  natural  sounds 
or  any  intellectual  constraint  is  of  doubtful  propriety. 
Because  of  this  the  descriptive  pieces  of  Berlioz  do 
violence  to  one's  sense  of  fitness,  and  we  resent  it 
when  some  one  proposes  to  interpret  Beethoven's 
Fifth  Symphony  as  a  philosophical  tract. 

No  such  complete  differentiation  has  taken  place  The  visual 
in  the  visual  arts,  and  it  is  perhaps  doubtful  whether  haps^under- 
it  ever  will  occur.     And  yet  there  are  signs  of  such  a  going  a  like 
movement.     We  are  certainly  much  more  willing  to 
separate  sculpture  from  painting  and  are  more  satis- 
fied with  the  colorless  form  of  things  than  were  even 
the  Greeks.     They  often  colored  their  marble  build- 
ings and  statuary, — a  treatment  which  we  should  now 
regard  as  in  bad  taste.     And  our  strong  interest  in 
work  in  black   and  white  is   further   evidence   that 
we   can    enjoy   visual    representations    from   which 
color    is    entirely   excluded.     The    natural    correla- 

1  I  must,  of  course,  leave  the  settlement  of  Wagner's  place  in  art 
to  others.  His  "music  dramas,"  especially  those  of  the  Ring  Cycle,  do 
not  seem  to  me  a  refutation  of  the  view  here  espoused.  The  music 
in  them  is  unsurpassed  as  decoration  or  atmosphere  for  the  great 
dramatic  movement;  but,  judged  by  itself  and  apart  from  this  ancillary 
function,  it  hardly  appears  to  reach  the  excellence  of  the  best  inde- 
pendent music.  And  while  his  librettos  are  probably  the  best  of  their 
kind,  yet  even  the  partisans  of  Wagner  would  hardly  wish  them  to  be 
compared,  as  dramas,  with  the  works  of  Sophocles  or  of  Shakespeare, 
s 


258 


Experimental  Psychology 


Non-imita- 
tive color 
has  as  great 
emotional 
value  as  mu- 
sical sound. 


tive  of  this  would  be  an  art  in  which  color  should 
come  to  the  very  front  —  an  independent  art  in 
which  hues  should  play  the  same  rdle  that  tones 
do  in  music.  The  nearest  approach  to  this  is  where 
the  colored  surface  has  ceased  to  be  immediately 
imitative,  as  in  certain  conventional  patterns  of  mo- 
saic or  fresco  or  weaving.  But  here  the  art  is  one 
of  color  and  spatial  design  together,  and  not  of  color 
alone.  And  ordinary  painting  permits  even  less 
freedom  in  the  use  of  color.  The  most  radical  color- 
ist  of  the  day  would  never  quite  dare  to  lay  his  pig- 
ment on  so  that  it  gave  no  suggestion  of  natural 
objects;  painting  is  bound  more  or  less  by  the  laws 
of  imitation  both  as  to  form  and  as  to  color.  If  an 
artist's  color  seems  extreme  and  wide  of  the  facts,  he 
will  usually  attempt  the  defence  that  at  least  he  him- 
self actually  does  see  such  tints  in  the  object.  But 
the  musician  is  entirely  free  from  any  such  restraints ; 
he  is  never  asked  to  show  that  natural  things  give 
forth  the  tones  and  harmonies  that  he  presents,  and 
that  he  is  merely  revealing  them  to  us.  Even  in  the 
well-known  passage  in  Beethoven  where  Fate,  it  is 
said,  is  knocking  at  the  door,  how  free  the  artist  is  to 
present  this  in  tones  that  it  would  be  impossible  to 
think  of  as  due  to  strokes  on  wood  !  It  is  given  chiefly 
by  the  strings,  and  the  abstract  rhythm  and  force  is 
in  fact  the  only  point  of  resemblance  to  the  object 
the  artist  may  have  had  in  mind. 

The  reason  why  no  similarly  free  use  of  color  has 
been  developed  does  not  seem  to  me  to  lie  in  the  char- 
acter of  color  itself.    Its  splendor  and  emotional  power 


Color  and  the  Fine  Arts  259 

is  certainly  not  less  than  that  of  sound.  And  if  given 
in  proper  sequences,  with  regular  variations  of  inten- 
sity or  tone,  it  is  capable  of  giving  us  the  feeling  of 
rhythm  that  music  offers.  Sound,  then,  has  no  in- 
herent advantage  over  color;  its  earlier  attainment 
of  an  independent  position  in  art  is  probably  due  to 
the  greater  mechanical  ease  with  which  it  can  be 
produced  and  rapidly  modified.  If  it  were  mechani- 
cally simpler,  nature  would  have  supplied  us  not  with 
a  voice,  but  with  some  kind  of  an  organ  for  the  emis- 
sion of  colored  lights  in  rapid  succession.  Think  of 
the  handicap  such  an  organ  would  have  given  in 
the  struggle  for  existence  !  how  it  could  have  been 
used  as  a  kind  of  search-light  for  prey,  or  in  commu- 
nicating with  distant  friends,  or  to  excite  admiration 
and  love  in  primitive  courtship !  Or  if  it  had  been 
possible  for  man  to  change  the  color  and  intensity  of 
fire  and  make  it  answer  his  bidding  at  the  instant,  with 
the  same  ease  with  which  he  can  strike  the  strings  of 
a  harp  or  change  the  pitch  and  volume  of  sound  from 
his  simple  pipes,  the  free  artistic  use  of  light  would 
have  been  as  inevitable  as  music.  It  is  fast  becom- 
ing possible  for  men  to  have  this  perfect  control  over 
brilliant  colors,  and  it  seems  to  me  probable  that  in 
the  distant  future,  when  the  unbeautiful  associations 
of  carbons  and  dynamos  and  insulated  wires  shall  have 
passed  away,  and  all  these  things  shall  be  thought  of 
as  having  existed  from  an  immemorial  past,  pure  its  artistic 
color  in  harmonious  combinations,  passing  in  stately  Possibilities. 
and  rhythmic  cadence  through  the  gamut  of  bright- 
ness and  of  hue,  and  the  whole  worked  out  with  be- 


26o  Experimental  Psychology 

ginning  and  climax  and  close  —  all  this  may  not  seem 
unfit  to  be  used  as  a  means  of  aesthetic  expression.^ 
That  a  display  of  color  itself,  apart  from  any  inherent 
imitative  meaning  in  its  arrangement,  is  capable  of 
producing  noble  effects  is  shown  by  the  feeUng  with 
which  men  have  always  watched  the  spectacle  of  the 
sunset. 
Conclusion.  But  art  is  long,  and  if  one  were  to  keep  merely  to 
the  psychology  of  it,  he  would  be  led  on  and  on.  The 
enjoyment  we  take  in  imitation  has  had  but  a  passing 
sentence ;  the  pleasure  we  find  in  expressing  our- 
selves ;  the  absolute  need  there  is  of  giving  expression 
to  our  nature ;  the  reasons  why  art  and  play  are  so 
refreshing,  —  all  these  have  not  had  a  word.  We 
have  only  noted  some  few  things  that  lay  within  and 
near  the  borders  of  the  experimental  work.  As  I 
said  at  the  beginning  of  the  preceding  chapter,  the 
experiments  confessedly  deal  with  but  the  rudiments 
of  the  artistic  impulse.  There  is  perhaps  no  need  of 
an  apology  because  they  do  not  usher  in  the  whole 
philosophic  truth.  They  have  brought  us  a  little 
nearer  to  a  complete  natural  history  of  art.  It  is 
easier  through  them  to  see  the  varied  features  of 
beauty,  and  to  mark  how  its  many  minute  details  con- 

1  An  elaborate  system  of  this  kind  has  recently  been  proposed  by 
Favre,  La  niusique  de  couleurs,  Paris,  1900.  He  points  out  how  differ- 
ent a  true  art  of  abstract  color  would  be  from  the  mere  "  play  "  of  our 
electric  fountains.  According  to  the  account  in  the  Revue  Philoso- 
phique,  January,  1901,  he  proposes  "scales"  and  "keys"  of  color.  I 
cannot  find,  however,  that  he  has  thought  of  the  great  possibilities 
involved  in  the  careful  application  of  rhythm.  The  opportunities  for 
its  use  in  a  color  succession  are  even  greater  than  in  the  case  of  suc- 
cessive sounds. 


Color  and  the  Fine  Arts  261 

tribute  to  the  total  effect.  If  they  assist  us  also  to 
understand  something  of  the  reasons  for  personal 
preference  and  for  the  historical  growth  and  separa- 
tion of  the  arts,  they  may  be  accounted  at  least  the 
beginning  of  an  excellent  work. 


CHAPTER  XIV 

THE  CONNECTION   OF  MIND  AND   BODY 

The  distinc-  The  distinction  between  mind  and  body,  spirit  and 
andbod^^^^  matter,  is  a  comparatively  late  achievement.  In  the 
youth  of  the  world,  men  were  neither  materialists  nor 
spiritualists.  For  them,  physical  processes  were  in- 
fused with  spirit,  while  spirit  itself  was  a  kind  of 
material  thing.  So  that  consciousness  could  be  re- 
garded as  on  the  same  plane  with  purely  physical 
processes,  like  digestion  or  breathing.  Homer,  for 
instance,  does  not  hesitate  to  say  that  Hephaestus, 
the  clever  mechanic-god,  made  golden  handmaids 
that  not  only  moved  about,  but  had  "  intelligence  in 
their  hearts "  and  "  skill  of  the  immortal  gods."  ^ 
Thinking  was  evidently  here  conceived  as  something 
that  a  well-contrived  machine  could  do.  With  a 
deeper  hold  on  life,  however,  men  begin  to  distin- 
guish between  the  things  of  the  flesh  and  those  of 
the  spirit;  mind  and  body  stand  out  in  strong  con- 
Probiem  of  trast,  and  it  then  becomes  a  question  what  the  con- 
nection of  the  two  may  be. 

Like  every  study  that  comes  close  to  the  moral  and 
religious  interests  of  men,  this  has  had  its  prejudices 

1  Iliad,  Bk.  XVIII,  11.  417  et  seqq.,  especially:  — 

T^s  kv  likv  viio<i  iarl  fierd,  ((>p€<Tlv,  iv  Sk  Kal  a^SiJ 

Kai  ffd^vos,  ddavdrwy  84  deCov  diro  epya  fcatrtv. 

262 


their  union. 


Fig.  55.  —  Sphygmograph. 


Fig.  56. —  Plethysmograph.     For  recording  changes  in  the  volume  of  the  arm, 
that  accompany  changes  in  the  mental  state. 


The  Connection  of  Mind  and  Body     265 

smaller  wave-like  changes  are  due  to  the  separate  pul- 
sations of  the  heart  which  force  the  blood  rhythmically 
into  the  extremities ;  and  since  the  blood-vessels  are 
elastic,  greater  pressure  makes  them  expand,  and 
with  less  pressure  they  contract.  The  volume  of  the 
arm  thus  changes  at  every  heart-beat.  The  upper 
curve  of  this  record  shows  the  normal  pulse  of  the 
forearm  during  mental  repose.  But,  near  the  begin- 
ning of  the  second  Hne  of  the  record,  at  the  point 
marked  by  the  arrow,  the  person  who  was  here  experi- 
mented upon  was  asked  to  multiply  22  by  14,  and  it 
is  clearly  seen  that  immediately  thereafter  the  form 


Fig.  57.  — The  upper  record  is  of  the  normal  pulse  in  the  forearm.  The 
lower  shows  effect  of  mental  arithmetic  (multiplying  22  X  14).  (From 
Mosso.) 

of  the  individual  waves  changes  so  that  there  is  no 
break  in  the  up-stroke,  as  there  was  before.  But, 
more  important  still,  the  general  level  of  the  curve 
is  different,  showing  that  the  volume  of  the  arm  for 
a  short  time  increased,  and  then  was  steadily  reduced. 
Far  more  striking  results  can  be  obtained  if  we  re- 
cord, not  the  change  of  volume  of  some  outlying 
member,  like  the  arm,  but  the  alterations  of  the  brain 


266  Experimental  Psychology 

Mosso's  ex-  itself.  Mosso,  the  famous  Italian  physiologist,  experi- 
fhTulin^^  °^  menting  on  several  unfortunates  whose  brains  had 
brain.  been  laid  bare  by  accident  or  by  necessary  surgical 

operation,  was  able  to  take  tracings  of  the  changes 
of  volume  of  the  brain  under  different  mental  condi- 
tions.i  He  found  that  an  increase  of  mental  action 
is  signalized  by  a  sudden  increase  in  the  size  of  the 
brain,  due,  no  doubt,  to  the  added  amount  of  blood 
which  is  immediately  forced  up  to  it.  The  accom- 
panying records  (Figs.  58,  59,  and  60)  were  taken 
during  experiments  on  an  Italian  peasant,  with  an 
arrangement  of  apparatus  in  principle  like  that 
already  shown  in  Fig.  56. 

In  the  first  of  these  (Fig.  58)  we  have  a  simultane- 
ous record  from  brain  and  forearm,  the  upper  curve 
of  this  figure  being  that  of  the  brain.  At  the  point 
marked  by  the  arrow,  the  man  was  required  mentally 


Fig.  58.  — Simultaneous  record  of  pulse  in  brain  (upper  curve)  and  fore- 
arm (lower  curve).  At  a  the  subject  is  required  to  multiply  8  X  12;  at 
CO  he  gives  the  answer.     (From  Mosso.) 

to  multiply  8  by  12,  and  at  w  he  gave  the  answer. 
It  is  noticeable  how  much  more  marked  is  the  change 
in  the  brain,  at  these  critical  points,  than  in  the  fore- 
arm. 

1  Uffier  den  Kreislauf  des  Blutes  im  menschlichen  Gehirn,  Leipzig, 
1 88 1.     Figs.  57-60  are  taken,  by  kind  permission,  from  this  work. 


i 


The  Connection  of  Mind  and  Body     267 

The  next  record  (Fig.  59)  was  taken  while  this 
peasant,  Bertino,  was  asleep,  and  shows  the  effect 
upon  his  brain  produced  by  calling  his  name  aloud, 
at    the    point    marked    by  the    arrow,  yet  without 


Fig.  59.  —  Record  of  brain  pulse  during  sleep.  At  the  point  marked  by 
the  arrow,  the  subject's  name  is  called,  without,  however,  awakening 
him.     (From  Mosso.) 

awakening  him.  Not  only  does  the  volume  of  the 
brain  change,  as  shown  by  the  general  rise  of  the 
curve,  but  the  individual  waves  have  a  different  form, 
having  elevations  on  both  sides  of  the  crest,  whereas 
before  this  stimulation  the  extreme  left-hand  eleva- 
tion of  each  was  the  highest. 


Fig.  60.  — Simultaneous  record  from  brain  (ist  and  3d  curves  from  bottom) 
and  forearm  (2d  and  4th) .  The  lower  two  curves  are  during  repose ; 
the  upper  two  during  strong  emotion.     (From  Mosso.) 

The  record  in  Fig.  60  was  taken   during  an   ex- 
periment that  was  in  progress  at  midday.     The  curve 


268  Experimental  Psychology 

at  the  very  bottom  shows  the  pulsations  of  the  brain 
while  the  man  was  at  perfect  ease,  the  curve  just 
above  it  being  the  simultaneous  record  from  the  fore- 
arm. Later  on,  he  was  upbraided  for  some  slight  move- 
ment which  disturbed  the  experiment,  and  became 
excited  and  chagrined.  The  third  and  fourth  curves 
from  the  bottom  are  a  simultaneous  record  from 
brain  and  forearm,  respectively,  taken  at  this  time; 
the  waves  of  the  brain-curve  are  wild  and  high,  as 
compared  with  those  taken  earlier.  Now,  at  the  point 
in  this  third  line  marked  by  the  arrow,  the  neighbor- 
ing church-bell  struck  the  hour  of  twelve  ;  the  curve 
suddenly  leaps  to  a  still  greater  height.  Mosso  found 
later  that  the  peasant  was  accustomed  to  cross  him- 
self at  noon,  and  say  his  Ave  Maria,  and  his  feeling 
of  embarrassment  at  not  being  able  to  perform  his 
simple  rite  is  doubtless  the  reason  why  the  stroke  of 
the  hour  made  such  a  sudden  and  marked  change  in 
a  record  already  showing  excitement  enough. 

The  meaning  The  rcsult  of  all  this,  and  of  much  more  of  the  same 
kind,^  is  to  bring  about  the  conviction  that  body  and 
mind  are  in  most  intimate  connection,  and  that  the 
intercourse  of  the  two  is  not  occasional,  but  is  con- 
stant. Formerly  we  believed  that  some  strong  emo- 
tional excitement,  or  a  definite  act  of  will,  must  be 
present  if  there  was  to  be  any  manifest  expression  of 
the  mental  state.     But  it  is  now  generally  accepted 

1  Considerable  work  has  been  Jone,  for  example,  in  noting  the 
connection  between  pleasure-pain  and  the  form  of  the  vascular  and 
respiratory  tracings.  The  latest  of  such  studies  is  that  of  Zoneff  and 
Meumann,  Fhilosophische  Siudien,  Vol.  XVIII,  p.  i. 


of  these 
experiments. 


The  Connection  of  Mind  and  Body     269 

that  the  body  reflects  every  shade  of  psychic  opera- 
tion ;  that  in  all  manner  of  mental  action  there  is  some 
physical  expression.  "All  consciousness  is  motor" 
is  the  brief  statement  of  this  important  truth ;  every 
mental  state  somehow  runs  over  into  a  corresponding 
bodily  state. 

Innocent  as  all  this  may  seem,  it   has   in   reality  They  revoiu- 
revolutionized  our  view  of  expression^  and  of  its  in  flu-  v°'^^^of°^'^ 


ex- 


ence  upon  mental  states.  We  used  to  suppose  that  pression." 
the  bodily  expression  of  what  was  going  on  in  the 
mind  was  of  no  great  importance  as  far  as  the  mind 
was  concerned ;  that  in  the  case  of  fear,  for  instance, 
there  would  still  be  fear  even  if  there  were  no  palpi- 
tation of  the  heart,  no  pallor,  nothing  of  what  old 
iEneas  felt  when  (as  he  says)  — 

Obstzpui,  steteruntque  comcB  et  vox  faucibus  hcesit. 

But  we  now  know  better ;  we  know  that  this  outward 
physical  expression,  as  we  call  it,  is  a  most  important 
thing ;  it  makes  the  fear  real.  The  feeling  of  what 
is  occurring  in  our  veins  and  muscles  rolls  back  upon 
the  mind  and  gives  the  mental  state  definiteness  and 
"body."  Without  the  physical  concomitants  and  the 
feelings  they  arouse,  the  mental  process  would  be 
pale  and  shadowy.  Half  the  fun  of  a  joke,  therefore, 
is  in  the  laughter  ;  half  the  sadness  of  sorrow  comes 
from  an  actual  depression  of  body  —  a  weight  of  . 
physical  distress. 

It  is  not  true,  then,  that  there  first  exists  a  mental  The  mental 
state  in  full  vigor,  which  later  operates  upon  the  fx^press^n^ 
physical  world.  On  the  contrary,  what  goes  on  in  are  one  and 
our  minds  never  is  really  there  until  it  is  expressed,  ^"^^p^""^  ^- 


270  Experimental  Psychology 

Externalizing  an  idea  in  some  way,  putting  it  off 
from  us,  so  that  it  may  return  upon  us  as  from 
without,  is  the  only  way  to  gain  possession  of  it  our- 
selves. We  must  try  to  articulate  the  thought,  speak 
it  to  some  one,  put  it  into  practical  use,  or  it  fails  to 
take  form.  Modern  physiological  psychology  thus 
points  out  that  there  is  an  essential  connection  be- 
tween body  and  spirit,  and  is  opposed  to  the  older 
doctrine  that  the  two  are  in  antagonism,  that  the 
body  and  the  sense-world  are  opposed  to  the  moral 
life,  —  a  doctrine  that,  developed  in  Plato,  found  ex- 
pression in  asceticism  and  the  life  of  the  hermit  and 
the  anchorite,  —  a  life  of  pure  contemplation,  of  mor- 
tification of  the  flesh,  as  opposed  to  physical  activity 
and  health.  Such  a  doctrine  is  unpsychological. 
The  body  is  not  a  clog  upon  the  mind;  it  is  not 
"a  muddy  vesture  of  decay"  that  hems  us  in.  It 
is  an  indispensable  factor  in  the  highest  develop- 
Characterof  ment  both  of  intellect  and  of  character.  A  really 
bodied'spirit.  disembodied  spirit  (the  ghost  believed  in  popu- 
larly is  never  quite  disembodied,  but  always  retains 
some  tenuous  shape),  a  spirit  absolutely  without 
a  body,  would,  so  far  as  we  can  now  see,  have  no 
point  of  contact  with  a  sensible  world,  no  oppor- 
tunity of  giving  sensible  expression  to  its  incipient 
mental  processes.  These  processes  would  have  no 
physical  reverberation,  and,  lacking  the  quality  by 
which  alone  they  could  become  real  to  others,  they 
would  soon  cease  to  be  real  to  the  person  himself. 
This,  I  imagine,  is  the  scientific  basis  for  the  old 
truth  that  "faith  without  works"  is  vain.  A  men- 
tal state  that  does  not  come  to  some  characteristic 


The  Connection  of  Mind  and  Body     271 

outward  expression  is  only  a  half-real  mental  state 
at  best. 

But  we  must  pass  to  another  field  of  investigation  n.  The  seat 
which  has  to  do  with  the  topic  before  us,  —  the  in-  °nJhebo'dy. 
vestigation  of  the  seat  of  consciousness.  Brought 
up,  as  we  are,  in  the  belief  that  the  brain  is  the 
chief  organ  of  the  mind,  it  seems  as  if  each  of  us  had 
some  direct  knowledge  that  thinking  takes  place  in 
the  head.  But  history  shows  that  the  unsophisticated 
man  is  ready  to  localize  his  mental  processes  almost 
anywhere  but  in  his  brain  —  in  his  heart  (as  Aristotle 
did)  or  elsewhere.  One  may  recall  the  expression, 
"my  reins  instruct  me  in  the  night  season."^  But 
having  found  that  the  brain  is,  in  some  peculiar  sense, 
the  organ  of  the  mind,  the  further  problem  arises, 
whether  the  mind  has  connection  with  all  parts  of 
the  brain  equally,  or  whether  there  is  a  still  more 
definite  seat  of  the  soul.  The  older  metaphysical 
definition  of  the  soul  —  that  it  is  a  simple  substance, 
and,  because  it  is  simple,  necessarily  without  exten- 
sion —  led  men  at  first  to  maintain  that  it  could  be 
present  only  at  some  single  mathematical  point  in  the 
brain.  Now  the  brain  is,  in  most  of  its  structure,  a 
double  organ :  there  are  the  two  halves  of  the  cere- 
brum, separated  by  a  deep  fissure;  there  are  two 
optic  thalamic  two  corpora  striata^  and  so  on.  But 
at  one  unique  place,  well  covered  under  the  mass 
of  the  hemispheres,  and  at  a  kind  of  geographical  The  pineal 
centre  of  things,  there  is  a  small  body  called  the  ^^^"'^^ 
pineal  gland,  which  has  not  the  double  structure  so 

1  Psalm  xvi.  7. 


272 


Experimental  Psychology 


The  ventri- 
I  cles  of  the 
brain. 


Phrenology 
and  the 
cerebral  con- 
volutions. 


common  in  the  other  parts.  Its  smallness,  —  a  very 
small  pea  is  about  its  size,  —  its  singleness,  its  central 
position,  made  it  seem  the  fit  habitat  of  the  spaceless 
mind ;  and  here  Descartes  supposed  the  soul  had  its 
seat,  governing  the  body  from  this  point  of  vantage, 
playing  upon  its  stops,  much  as  an  organist  at  the 
keyboard  controls  his  instrument.  But  later  it  seemed 
more  suitable  to  think  of  the  soul  as  in  less  gross  sur- 
roundings ;  so  its  abiding  place  was  changed  to  the 
fluid  in  certain  cavities  of  the  cerebrum  known  as  the 
ventricles;  here  it  would  not  be  actually  embedded 
in  the  nervous  substance ;  it  would  govern  the  body 
through  the  brain,  and  yet  without  such  immediate 
material  contact.  Thus  did  men,  in  their  theory, 
guard  the  spirit  from  contamination. 

Strange  to  say,  it  was  Gall  and  the  phrenologists 
who  drew  attention  away  from  these  curious  specula- 
tions and  emphasized  the  physiological  importance  of 
the  convolutions^  —  the  outer  surface  of  the  hemi- 
spheres,—  teaching  at  the  same  time  that  different 
portions  of  the  surface  were  given  over  to  different 
spiritual  functions :  acquisitiveness,  combativeness,  rev- 
erence, and  the  like.  This  notion,  that  the  nervous 
counterparts  of  the  various  mental  functions  are 
scattered  about  in  the  brain,  was  at  first  strenu- 
ously opposed,  and  much  was  made  of  such  evidence 
as  that  afforded  by  the  celebrated  crow-bar  case,  where 
an  enormous  wound  in  the  brain  resulted  in  no  per- 
manent mental  trouble  whatever.  And,  indeed,  there 
was  no  very  good  support  for  this  doctrine  of  scat- 
tered localization  until  about  the  year  1863,  when 
Broca  made  the  interesting  and  important  discovery 


MOTOR-TACTUAL  REGION 


VISUAL  REGION  M  J 


*  AUDI  TORY  REGION 

Fig.  6i.  —  Diagram  of  the  outer  surface  of  the  right  hemisphere  of  the  brain. 
The  dotted  areas  represent  the  visual,  auditory,  and  motor-tactual  "  cen- 
tres," respectively.     (After  Flechsig.) 


VISUAL  REG  I C 


MOTOR-TACTUAL  REGION 


OLFACTORY  REGION 


Fig.  62.  —  Diagram  of  mesial  surface  of  the  left  hemisphere  of  the  brain.  The 
dotted  areas  represent,  respectively,  the  visual,  motor-tactual,  and  olfactory 
"  centres."     (After  Flechsig.) 


The  Connection  of  Mind  and  Body     273 

that  if  the  third  frontal  convolution  of  the  left  side,  Broca's  ^ 
in  right-handed  persons,  was  disordered  (the  region  ^'^covery. 
to  which  phrenologists  ascribe  "  constructiveness  "), 
speech  became  a  hopeless  tangle  of  sounds  —  a  dis- 
ease  now   known  as  aphasia.     This  was   really  the 
first  of  the  great  modern  discoveries  in  brain-localiza- 
tion.    The  work  was  thereafter  carried  on,  partly  by  The  later 
experiment   on   living   animals,  by  laying   bare   the  ^ra^in^ocaii 
brain  and  electrically  stimulating  it  at  different  points,  zation. 
or  by  carefully  removing   portions  of   the   nervous 
matter  and  noting  any  change  in  the  animal's  beha- 
vior.    But  the  work  has  been  marvellously  aided  by 
the  use  of  chemical  stains  which  have  the  power  of 
bringing  out  the  inner  structure  of  the  brain.     This 
post-mortem  staining  and  the  careful  examination  of 
the  effects  of  local  brain-disease  have  been  the  main 
reliance  in  learning  what  parts  of  the  human  brain 
are  of  most  importance  for  the  mind. 

The  result  of  all  this  study  has  been  to  show  that,  The  motor 
in  the  first  place,  there  is  a  wide  zone,  —  beginning  ^°^®' 
near  the  centre  of  the  top  of  the  head  (the  seat  of 
**  veneration,"  according  to  the  phrenologists)  and 
running  downward  and  forward, — which  has  to  do 
chiefly  with  the  conscious  control  of  the  muscles.  It 
is,  for  this  reason,  usually  called  the  ** motor"  zone, 
although  in  all  probability  it  is  quite  as  much  a  re- 
gion for  the  sense  of  touch  and  for  all  those  feel- 
ings which  come  to  us  from  our  muscles  and  skin 
(Figs.  61  and  62).  Even  the  brain-connections  of  spe- 
cial groups  of  muscles  with  this  region  are  now  pretty 
accurately  known  ;  so  that  the  brain-surgeon,  once  he 
is  certain  that  this  surface  of  the  brain  is  affected, 


274 


Experimental  Psychology 


Sensory 
centres. 


Cautions 
as  to  these 
results. 


can  tell  with  considerable  security  what  particular 
portion  of  it  is  diseased,  according  as  there  is,  say, 
paralysis  of  the  right  leg,  or  of  the  left  hand,  or  of 
the  muscles  involved  in  speech.  Besides  this  motor 
region,  or,  as  we  might  just  as  well  call  it,  the  zone  of 
organic  sensations,^  special  regions  have  been  dis- 
covered for  sight,  hearing,  and  smell.  The  region 
for  smell,  as  we  might  expect,  is  found  to  be  located 
at  the  lower  inner  surfaces  of  the  cerebrum  that  lie 
not  far  from  the  upper  wall  of  the  nasal  cavity.  The 
nervous  centre  for  hearing  lies  on  either  side  of  the 
brain  in  what  is  called  the  region  of  Wernicke, — after 
its  discoverer,  —  the  place  to  which  "  secretiveness  " 
had  been  attributed.  And,  finally,  in  defiance  of  all 
common-sense,  the  centre  for  sight  lies  in  the  very 
back  of  the  head.  Laura  Bridgman's  brain,  for  in- 
stance, showed  a  marked  thinning  out  of  the  cortex 
of  this  rear  region  of  the  brain ;  it  had  not  been  used 
from  early  childhood,  and  had  remained  undeveloped.^ 
On  the  basis  of  these  discoveries,  one  is  tempted 
to  say  that  the  function  of  sight,  for  instance,  is  lo- 
cated in  the  posterior  region  of  the  brain.  But  this 
is  only  a  careless  half-truth.  Probably  all  that  we 
should  be  conscious  of,  if  this  region  alone  were 
active,  would  be  the  naked  light  impressions  stripped 
of  all  association  and,  therefore,  without  connection 
and  significance.     For  sight  is  much  more  than  light 


1  Flechsig  (following  Munk),  Gehirn  und  Seek,  Leipzig,  1896, 
p.  62.     Figs.  61-65  ^^^  taken,  by  kind  permission,  from  this  work. 

2  Donaldson,  "  The  Extent  of  the  Visual  Area  of  the  Cortex  in  Man, 
as  deduced  from  the  Study  of  Laura  Bridgman's  Brain,"  American 
Journal  of  Psychology ^  Vol.  IV,  p.  503. 


The  Connection  of  Mind  and  Body     275 

and  color ;  we  must  be  able  to  make  out  what  these 
signify;  we  must  be  able  to  translate  them  into 
tactual,  auditory,  or  olfactory  terms.  We  really  see 
things  with  practically  our  whole  brain,  and  not  alone 
with  what  we  call  the  visual  centre.  If  a  convolution 
of  the  brain  cannot  cooperate  with  other  convolutions, 
it  is  as  good  as  lost.  Thus  in  a  patient  of  whom  we 
have  a  report  by  Heubner,  disease  partially  discon- 
nected the  auditory  region  from  the  other  parts  of  the 
brain-surface ;  under  these  circumstances  the  person, 
it  is  true,  could  repeat  mechanically  any  words  dic- 
tated to  him,  —  he  thus  retained  his  sense  of  sound, 

—  but  he  was  absolutely  unable  to  know  what  the 
sounds  meant.  For  any  very  important  function, 
then,  the  various  parts  of  the  brain  act  as  a  whole, 
and  the  phrenologists*  notion  is  absurd  that  we  imag- 
ine with  one  isolated  portion  of  the  brain,  and  recol- 
lect with  another,  and  pass  judgment  with  still  a  third. 
In  the  adult  brain,  at  least,  well-nigh  all  parts  of  the 
brain  together  take  a  hand  in  any  significant  action. 

Recent  discoveries  show  that  this  is  far  less  the  Peculiarities 
case  in  the  infant's  brain.     The  development  soon  brafn^"^^"*^ 
after  birth  shows  that  the  different  parts  of  the  gray 
surface  grow  up  in  comparative  separation.     The  very 
earliest  to  develop  are  the  centres  of  touch  and  smell 

—  the  functions  which  the  animal  uses  most ;  so  that 
the  babe  is  at  first  on  this  animal  plane,  where  smell 
and  touch  are  the  chief  avenues  of  the  mind.  The 
next  to  appear  is  the  sense  of  sight ;  and  last  of  all 
comes  the  sense  of  hearing. 

Quite  as  interesting  as  this  serial  development  of 
the   different  senses  is  the  fact  that  these  different 


276  Experimental  Psychology 

regions — of  touch,  smell,  hearing,  and  sight  —  have 
at  first  no  apparent  nervous  connections  with  one 
another.  Not  until  almost  the  third  month  after  birth 
are  there  the  rudiments  of  fibres  uniting  these  various 
sensory  tracts.  ^  This,  of  course,  means  that  none  of 
those  conscious  associations  is  as  yet  possible  between 
one  sense  and  another,  which  adults  have  when  the 
sight,  for  instance,  of  heliotrope  suggests  its  perfume, 
or  when  the  sound  of  a  person's  voice  recalls  his  face. 
It  is  difficult  for  us  to  conceive  in  what  a  disjointed 
condition  the  child's  consciousness  must  be  before  this 
time,  —  sights  that  suggest  no  sounds,  touches  that 
arouse  no  thought  of  taste  or  smell,  each  item,  as  it 
appears  in  the  mind,  being  blankly  received  for  just 
what  it  is,  pointing  to  nothing  beyond  itself,  and,  for 
this  reason,  being  as  nearly  without  form  and  void  as 
anything  in  the  mental  life  can  be  and  still  be  mental. 

The  value  of  With  this  all  too  brief  account  of  these  discoveries 
foroursSdy  ^  ^^^^  leave  the  concrete,  experimental  part  of  the 
subject.  But  the  importance  of  such  facts  as  these 
for  the  natural  history  of  the  mind  seems  to  me  so 
evident  that  I  cannot  at  all  agree  with  a  recent  writer 
of  high  standing  in  psychology  who  has  soberly  urged 
that  the  physiologists  cannot  help  us  in  the  study  of 
psychic  phenomena  —  that  physiology  is  constantly 
aided  by  psychology,  but  is  of  necessity  unable  to  give 
anything  in  return.  On  the  contrary,  these  studies 
of  the  nervous  system  offer  a  means  of  discovering 
purely  psychological  facts  that  we  can  unearth  in  no 
other  way.     How  otherwise  than  by  a  physiological 

1  Flechsig,  oJ>.  ci/.,  p.  106. 


Fig.  63.  —  Section  of  infant's  brain,  one  month  after  birth  (stained).  The 
relatively  advanced  development  of  the  lower  centres  is  shown  by  their 
taking  a  strong  stain.     (After  Flechsig.) 


>     VISUAL  CONNECTON 


"  AUDITORYCONNECTON 


Fig.  64.  —  Stained  section  of  infant's  brain  at  beginning  of  second  week  after 
birth.  The  relative  backwardness  of  hearing,  as  compared  with  sight,  is 
shown  by  the  faintness  of  the  auditory  connection  as  compared  with  the 
visual.     (After  Flechsig.) 


Fig.  65. —  Stained  section  of  infant's  brain  about  tive  months  after  birth. 
Showing  the  advance  in  the  development  of  the  higher  centres,  as  com- 
pared with  Fig.  63.     (After  Flcchsig.) 


The  Connection  of  Mind  and  Body     277 

investigation  could  we  yet  have  said,  for  instance,  in 
what  order  the  infant's  consciousness  of  sense-im- 
pressions arrives  or  when  the  interconnections  among 
them  are  built  up  ?  The  value  of  the  physiological 
work  the  psychologist  must  cordially  acknowledge. 
And  while  it  is  true  that  the  brain  is  not  the  mind, 
and  that,  in  order  to  translate  brain-discoveries  into 
psychological  discoveries,  some  knowledge  of  the 
purely  mental  realm  is  necessary,  yet  it  would  seem 
highly  ungracious  to  withhold  our  appreciation  for 
that  reason  and  stiffly  to  insist  on  the  exclusive  worth 
of  the  introspective  method.  The  value  of  the  intro- 
spective method  is  sufficiently  patent  to  free  us  from 
the  need  of  proclaiming  it  both  in  season  and  out  of 
season. 

But  on  deeper  grounds  than  these  there  is  apt  to  what  is  the 
be  a  clash  between  the  students  of  mind  and  those  of  07^41^°" 
the  brain.     The  physiologists  often  give  the  impres-  and  mind? 
sion  that,  in  their  view,  the  brain-process  is  the  only 
real  process  there  is,  and  that  mental  phenomena  are 
but  a  special  way  of  regarding  the  action  of  the  brain. 
Or  if  they  do  distinguish  the  nervous  from  the  psychic 
act,  the  psychic  is  considered  as  a  mere  effect  or  ex- 
pression of  the  activity  of  the  brain.     Now  when  we 
speak  of  cause  and  effect,  we  almost  invariably  imply 
that  the  cause  is  a  much  nobler  and  more  significant 
thing  than  its  effect.     All  of  us,  for  instance,  would 
prefer  to  be  causes  in  the  world  rather  than  effects.) 
So  that  when  the  brain-specialist  announces  that  he 
has  discovered  in  the  gray  cerebral  matter  the  cause 
of  mental  operation,  the  lover  of  mind  naturally  re- 
sents this  as  a  degradation  of  the  object  of  his  affec- 


278 


Experimental  Psychology 


tion.  If  either  is  to  be  cause,  he  feels  that  this  office 
should  fall  to  the  mind ;  the  mind  is  the  very  kernel 
of  personality,  the  saat  of  morals  and  intelligence, 
and  must  never  be  regarded  as  subject  to  the  beck 
and  call  of  matter. 


The  more 
prominent 
theories : 
interaction 
and  parallel- 
ism. 


We  have,  then,  a  number  of  doctrines  in  glaring 
opposition.  In  the  first  place,  there  is  the  view  that 
the  brain  either  is  the  mind  or  at  least  regulates  the 
mind;  and,  over  against  this,  is  the  conviction  that 
the  mind  is  superior  to  the  brain  and  operates  it.  But 
this  extreme  opposition  is  usually  softened  so  that 
now  one  side  and  now  the  other  has  the  upper  hand  — 
the  doctrine  of  interaction  between  mind  and  brain. 
Finally,  there  is  another  compromise  theory  that 
has  a  large  and  influential  following  at  the  present 
day,  —  a  theory  persisting  from  the  times  of  Geulinx, 
Spinoza,  and  Leibnitz,  that  neither  the  brain  controls 
the  mind  nor  does  the  mind  control  the  brain,  but  that 
they  run  in  essential  independence,  side  by  side,  like 
two  clocks,  both  telling  in  their  own  way  a  consistent 
story,  and  yet  neither  of  them  exerting  any  influence 
upon  its  companion.  This  is  the  doctrine  of  parallel- 
ism. According  to  parallelism,  there  is  no  real  inter- 
action between  mind  and  brain;  the  mind  does  not 
control  the  brain ;  neither  does  the  brain,  the  mind ; 
they  are  simply  in  harmony.^ 


1  For  brevity's  sake  I  have  taken  what  is  historically  the  main  cur- 
rent of  parallelism.  But  the  prestige  of  the  word  has  led  many  to  call 
themselves  parallelists,  whose  views  in  regard  to  the  relation  of  brain 
and  mind  are  most  divergent. 

It   seems   to  me  that  if  the  term  "parallelism"  is  to  have  any 


The  Connection  of  Mind  and  Body     279 

We  cannot  here  review  the  strong  evidences  which  Reflex  action 
each  of  these  views  presents.  Only  a  single  illustra-  {^1"°^  ^^^^^' 
tion  in  regard  to  parallelism  can  be  presented.  The 
facts  of  reflex  action,  —  for  instance,  that  a  frog 
deprived  of  its  cerebrum  will  croak,  and  swim,  and 
perform  other  complicated  actions  under  circum- 
stances that  preclude  the  thought  that  its  mind  is 
controlling  its  members,  —  such  facts  as  these  have 
led  many  to  believe  that  all  bodily  acts  are  essentially 
of  this  reflex  type.  If  the  body  is  capable  of  doing 
so  much  without  mental  guidance,  as  reflex  action 
shows,  why  not  suppose  that  the  body,  of  itself,  with- 
out help  from  the  mind,  is  capable  of  all.?  And  if 
it  can  perform  its  many  functions  without  mental  aid, 
there  seems  even  less  difficulty  in  the  other  half  of 
the  theory  that  the  mind  performs  its  acts  without 
aid  from  the  body.  According  to  parallelism,  then, 
it  is  an  illusion  to  believe  that  the  mind  controls  the 
body.  The  body  is  an  automaton,  haunted  by  a 
mind,  and  the  experiences  of  the  mind  correspond  to 
the  doings  of  its  automaton  body,  and  some  of  the 
doings  of  the  body  correspond  to  acts  of  its  indwell- 
ing mind.  But  there  is  no  real  cause-and-eff ect  relation 
between  these  two  classes  of  acts.  The  bodily  acts 
are  caused  solely  by  other  physical  acts ;  the  mental 
events  are  caused  solely  by  other  mental  events. 

definite  meaning  at  all,  it  should  imply,  as  it  has,  in  the  main,  histori- 
cally :  — 

(i)  That  every  mental  process  has  a  fixed  cerebral  process  regularly 
accompanying  it  temporally  (and  not  just  "logically"),  and 

(2)  That  there  is  no  causal  connection  between  the  corresponding 
mental  and  cerebral  processes. 


28o 


Experimental  Psychology 


with  this 
view. 


But  sense-  On  first  hearing  a  theory  like  this,  one  is  apt  to 

hardTo'°''  '^  ^^^^  ^^^^  ^^^^^  ^^^  plenty  of  known  facts  to  disprove 
reconcile  it.  But  such  is  not  the  case.  Almost  everything  that 
we  know  about  the  mind  and  body  could,  perhaps,  in 
an  extremity,  find  a  place  within  this  view.  At  the 
same  time  there  is  a  class  of  facts  that  require  some 
torturing  to  make  them  submissive  to  the  theory, 
particularly  the  facts  of  sensation  and  perception. 
Sense-perception  is  the  crux  of  parallelism  and  will 
some  day,  I  fear,  be  its  death.  The  experience  of 
seeing  a  bright  light  or  of  hearing  a  loud  sound  is 
quite  as  truly  a  mental  occurrence  as  is  a  conception 
or  a  train  of  reasoning,  and  according  to  parallelistic 
principles  must  be  explained  by  its  mental  antece- 
dents without  calling  in  any  physical  influence  what- 
ever. When  you  are  startled  from  a  revery  by  some 
crash  in  the  street,  caused,  let  us  say,  by  a  falling 
sign,  your  sudden  mental  impression  (this  theory  has 
to  assume)  is  not  caused  by  the  physical  disturbance 
without,  but  by  some  mental  processes  essentially 
disconnected  with  the  outer  world.  While  physical 
nature  has  been  rusting  away  the  fastenings  and 
stirring  the  wind  that  brings  down  the  sign,  the  inner 
processes  of  your  own  mind,  and  of  the  minds  of 
every  one  else  in  the  neighborhood  who  hears  the 
noise,  have  been  silently  preparing  to  call  forth 
sound-sensations  of  similar  loudness  and  jangle  in 
the  various  persons,  just  in  the  nick  of  time  when 
the  sign  falls  and  the  air-waves  cause  the  ner- 
vous disturbances  that  dart  inward  to  the  brain- 
cortex.  When  one  remembers  that  not  a  shred  of 
evidence  exists  of  any  antecedent  mental  processes 


The  Connection  of  Mind  and  Body     281 

that  might  cause  the  sensations  of  noise  (or  of  any  other 
similarly  unexpected  irrupting  impression),  he  begins 
to  appreciate  something  of  the  enormity  of  this 
theory.  It  separates  on  purely  a  priori  grounds  phe- 
nomena that  empirically  have  every  evidence  of  causal 
connection.  It  thus  leaves  the  world  of  experience 
in  a  disjointed  condition  that  natural  science  will,  as 
time  goes  on,  be  less  and  less  inclined  to  tolerate.  ^ 

But  for  still  other  reasons  it  seems  probable  that  Parallelism 
parallelism  will  in  the  end  die  of  neglect.  For  eloiutfonf^ 
the  influence  of  evolution  is  directly  against  it.  The 
machinery  by  which  evolution  moves  is  such  that 
every  important  and  wide-reaching  fact  in  the  world 
holds  its  place  there  only  because  it  is  of  service. 
Every  significant  and  persistent  strain  in  human 
or  in  animal  life  can  be  accounted  for  only  on  the 
supposition  that  it  is  of  use  in  maintaining  the  crea- 
ture or  its  species  upon  the  earth,  and  because  of  its 
use  it  has  been  encouraged  by  selection. 

Now  paralleHsm  is  in  conflict  with  this  biological 
principle  of  utility.  For,  if  the  mind  only  seems  to 
influence  the  body,  while  in  reality  all  physical  acts 
spring  solely  from  physical  causes,  then  there  is  no 
accounting  biologically  for  the  presence  and  persist- 
ence of  a  reasonable  and  practical  and  social  mind, 
such  as  accompanies  the  bodies  of  most  men,  as  well 
as  of  some  animals.  It  becomes  at  best  a  mere 
by-product  or  casual  accompaniment  of  processes 
that  are  biologically  significant.  If  parallelism  were 
true,  an  entire  absence  of  the  mental  stream,  or 
the  presence  of  a  consciousness  which  took  no  in- 
terest in  the  welfare  of  the  body,  would  have  been  no 


282  Experimental  Psychology- 

handicap  whatever.  A  mind  that  preferred  cold 
and  hunger  and  pain  and  unsocial  ways  would, 
physically  speaking,  be  at  no  disadvantage  if  only 
its  body  preferred  warmth  and  food  and  good 
society.  Persons  with  well-adapted  bodies,  but  with 
ill-adapted  minds,  could  then  flourish  without  let 
or  hindrance.  There  would  be  no  path  by  which 
natural  selection  could  head  off  and  destroy  such 
monstrosities,  and  consequently  their  kind,  which  in 
the  numberless  chance  variations  would  be  sure  to 
occur,  would  be  as  Ukely  to  survive  as  any  other. 
As  far  as  biology  is  concerned,  parallelism  is  con- 
sequently, as  Mr.  F.  H.  Bradley  has  said,  a  doctrine 
of  the  uselessness  of  the  soul.^  And  in  the  same 
way  it  is,  psychologically  speaking,  a  doctrine  of  the 
uselessness  of  the  body.  If  all  the  efficient  causes  of 
experience  are  to  be  found  in  the  mind  alone,  as 
parallelism  maintains,  then  the  body  is  a  useless 
companion  of  the  spirit,  and  has  no  essential  place  in 
its  history. 

The  doctrine  of  parallelism,  therefore,  is  bound  to 
pass  away,  not  only  because  we  can  point  to  definite 
facts,  Hke  sensation,  that  can  be  brought  within  it 
only  by  violence,  but  also  because  it  is  not  in  keeping 
with  the  principles  of  evolution  and  with  the  even 
broader  principle  that  the  various  facts  of  experience 
cannot  be  kept  insulated  from  one  another.  It  runs 
counter  to  the  general  trend  of  our  modern  thought, 
and  for  this  reason  it  is  at  a  hopeless  disadvantage  in 
the  struggle  for  acceptance. 

1  «*0n  the  Supposed  Uselessness  of  the  Soul,"  Mind,  N.  S.,  Vol.  IV, 
p.  176  ;  cf.  also  the  fifth  chapter  of  James's  Principles  of  Psychology. 


The  Connection  of  Mind  and  Body     283 

What,  then,  is  the  standing  of  the  alternative  notion.  The  theory  of 
that   mind   and   body   really   influence   each   other?  *^t^'^^'^t^°"' 
What  are  the  difficulties  in  such  a  view,  and  wherein 
is  its  strength  ? 

The  main  trouble  is  that  mind  and  body  seem  to  be  so  The  two 
absolutely  heterogeneous  that  it  is  difficult  to  see  how  sides  seem 
one  can  act  upon  the  other.     It  is  much  as  if  we  were  rogeneous. 
to  attempt  to  boil  water  with  the  theory  of  probabilities. 
The  terms  which  we  try  to  unite  stare  vacantly  at  each 
other,  and  cannot  be  brought  into  any  manner  of  in- 
tercourse.    It  seems  reasonable  that  matter  should 
influence  matter,  or  mind,  mind ;  but  that  conscious- 
ness, which  is  immaterial  and  unextended,  should  pro- 
duce changes  in  the  brain,  which  has  entirely  different 
attributes,  —  this  has  been  felt  by  many  to  be  at  vari- 
ance with  the  principles  of  modern  science. 

It  is  at  variance,  in  the  first  place,  many  think,  with  Causal  con- 
the  ordinary  conception  of  cause  and  effect.     For  if  seTms  ^  im- 
two  things  —  an  action  of   the  brain  and    its  corre-  piyquanti- 
sponding  mental  process  —  are  to  stand  in  a  causal  equality. 
relation,  is  it  not  necessary  that  they  should  be  some- 
how comparable  in  quantity  ?     Is  it  not  always  as- 
sumed  that  the   effect   has    a    certain    quantitative 
relation  to  the  cause,  and  that  what  the  cause  loses 
the  effect  gains  .?    But  how  can  we  ever  say  how  many 
units  of  physical  energy  are  the  equivalent  of  a  mental 
desire  or  resolve  .-*     The  two  lie  in  different  spheres, 
are  incomparable,  and  consequently  (it  is  held)  the 
one  cannot  produce  the  other. 

The  force  of  this  objection  is  somewhat  broken  by  Weakness  of 
a  number  of   reasons.     In  the   first   place   there   is  *^sobjec- 

^  tion. 

nothing  sacred  and  inviolable  in  the  prevalent  form 


284  Experimental  Psychology 

The  idea  of    which  the  Conception  of  cause  has  taken  on.     That 
cause.  there  should  be  a  quantitative  equation  between  cause 

and  effect  is  not  one  of  those  truths  that  are  axio- 
matic ;  it  has  simply  come  about  as  a  helpful  device  for 
dealing  with  phenomena  in  the  physical  world  and  of 
getting  shorthand  formulas  (to  use  Mr.  Karl  Pearson's 
term)  for  expressing  them.  But  what  serves  well 
when  we  confine  our  investigations  to  the  physical 
world  may  not  prove  most  useful  when  we  try  to 
cover  the  larger  field  that  includes  both  physical  and 
mental  things.  The  successful  description  of  this 
larger  realm  may  require  us  to  modify  our  notion  of 
the  causal  connection,  so  that  quantitative  equivalence 
shall  be  less  strongly  insisted  on.  If,  for  instance, 
the  definite  evidence  both  that  the  mind  is  efficacious 
in  the  physical  world  and  that  nervous  states  influence 
the  mind  —  if  this  evidence  continues  to  accumu- 
late at  the  rate  that  it  has  in  the  last  decade,  we 
may  well  be  forced  to  give  up  our  unnatural  paral- 
leHstic  way  of  describing  the  relation  here,  frankly 
admit  a  cross-causal  connection  between  mind  and 
body,  and  rearrange  our  notion  of  causality  so  as  to 
fit  the  mass  of  empirical  facts. 
Quantitative  In  the  sccoud  place,  if  quantitative  equivalence  is, 
notTmpos"  ^^  however,  to  be  regarded  as  indispensable  to  a  causal 
sibie.  connection,  it  is  not  impossible  that  this  requirement 

may  be  met.  A  quantitative  treatment  of  mental 
phenomena  does  not,  to  many,  appear  an  utter  absurd- 
ity. The  preceding  chapters,  especially  the  one  on 
"  The  Possibility  of  Mental  Measurements,"  have 
given  what  seem  to  me  the  indications  that  it  is  not 
only  theoretically  possible  to  deal  with  certain  aspects 


The  Connection  of  Mind  and  Body     285 

of  mind  quantitatively,  but  that  there  has  been  con- 
siderable practical  success  in  doing  this.  And  while 
it  may  not  be  feasible  to  say  beforehand  how  much 
nervous  energy  is  the  equivalent  of  any  given  mental 
fact,  and  only  experiment  can  determine  this,  yet 
the  same  is  true  when  we  keep  to  the  physical 
world.  The  mechanical  equivalent  of  a  given  quan- 
tum of  heat  has  to  be  found  by  experiment,  and 
could  never  have  been  argued  out  a  priori.  The 
quantitative  correlation  is,  in  the  first  instance,  "  em- 
pirical," and  a  causal  connection  is  felt  to  exist  long 
before  there  is  any  assurance  of  these  exacter  mathe- 
matical relations.  The  chief  evidence  of  a  causal  con- 
nection between  heat  and  mechanical  motion  is  the 
frequent  occurrence  of  one  with  the  other,  and  the 
variation  of  one  as  the  other  varies.  Only  later,  and 
as  an  extra  refinement,  is  it  presumed  that  the  energy 
in  the  two  cases  is  at  bottom  identical  and  to  be 
measured  possibly  by  some  identical  unit.  Now  as 
to  the  cerebral  and  mental  processes  that  would  stand 
in  a  causal  relation,  the  evidence  is  increasingly 
strong  not  only  that  they  frequently  occur  together, 
but  that  they  concomitantly  vary  in  quantity.  In  the 
case  of  sensation  and  stimulation,  to  take  by  no  means 
the  only  example,  there  is  found  a  rough  quantitative 
correspondence  between  the  two  terms,  even  though 
the  more  exact  nature  of  that  correspondence  be 
variously  judged  according  to  the  special  way  in 
which  we  interpret  Weber's  Law. 

And  as  a  final  (though,  perhaps,  a   less  cogent)  Difficulty 
reason   for   not  giving  too  much  weight  to  this  ob-  ^^^"ica/^^ 
jection  based  upon  quantity,  it  might  be  urged  that  an  realm. 


286  Experimental  Psychology 

exact  equivalence  between  cause  and  effect  does  not 
seem  to  be  always  verified  even  in  the  physical  world. 
Ostwald,  the  distinguished  German  chemist,  has 
recently  referred  to  certain  substances  that  by  their 
mere  presence,  without  any  discoverable  loss  on  their 
part,  assist  other  substances  to  produce  a  chemical 
reaction.  For  instance,  if  finely  divided  platinum  be 
introduced  among  certain  gases,  the  latter  will  com- 
bine much  more  rapidly  than  if  the  platinum  were  not 
there,  and  yet  the  platinum,  although  it  has  thus  been 
effective  in  bringing  about  the  combination  of  these 
other  substances,  is  in  exactly  the  same  state  after  it 
has  produced  this  effect  as  before.^  In  such  instances 
as  this  the  cause  does  not  appear  to  have  surrendered 
a  certain  quantity  of  its  own  being  to  have  it  reappear 
in  equal  amount  in  its  result.  No  equation  between 
them  is  possible.  These  and  similar  phenomena 
may  force  us,  more  and  more,  to  the  view  that  by 
cause  we  mean  simply  the  total  set  of  circumstances 
under  which  any  event  regularly  occurs.  Whatever 
is  indispensable  for  the  occurrence  of  any  event  we 
must  number  among  its  causes,  whether  the  various 
items  be  of  the  same  nature  or  not,  or  whether  the 
quantum  of  one  process  alters  in  proportion  to  the 
Hume's  view  cvcnt  which  issucs  from  it.  Under  this  view,  which 
of  cause.  j^  ^^  bottom  the  one  which  Hume  long  ago  made  us 
f  amiHar  with,  there  is  nothing  absurd  in  believing  that 
mental  events  are,  on  occasion,  to  be  numbered  among 
the  causes  of  physical  acts,  and  vice  versa. 

1  Ostwald,  "  Chemische  Theorie  der  Willensfreiheit,"  Verhandlungen 
der  koniglich-sachsischen  Gesellschaft  zu  Leipzig^  Math.-Phys.  Classe, 
Vol.  XLVI,  p.  334. 


at  times 
contributes. 


The  Connection  of  Mind  and  Body     287 

But  to  say  that  mind  is  a  cause  of  physical  events  No  bodily 
does  not  mean  that  an  act  of  our  body  ever  occurs  phlroLgkai 
solely  by  act  of  the  mind  and  without  suitable  antecedents, 
physical  antecedents.  Every  one  must  admit  that 
for  many  occurrences,  like  that  of  reflex  action, 
the  physical  antecedents  are  everything.  For  other 
acts,  like  those  of  will,  this  doctrine  of  mental  causa- 
tion in  the  physical  world  would  mean  that,  how- 
ever many  physical  antecedents  you  may  discover, — 
heredity,  or  disease,  or  habit,  or  physical  excite- 
ments of  the  moment,  —  these  do  not  fully  explain 
the  act.  The  mind,  as  well  as  the  body,  has  con-  Yet  the  mind 
tributed  its  share  to  form  the  total  situation  out  of 
which  the  action  springs.  Consciousness  might  here 
be  compared  to  the  scene  which  impresses  itself  upon 
a  photographic  plate.  The  scene  is  not  the  sufficient 
cause  of  the  photograph ;  it  is  an  indispensable  fac- 
tor, and  so  must  be  numbered  among  the  causes  of 
the  picture,  but  the  picture  depends  also  upon  the 
light,  depends  upon  the  lens,  upon  the  plate,  and 
the  chemicals  employed  in  developing  it.  So,  too,  the 
inner  act  of  will  cannot  be  impressed  upon  the  world 
by  its  own  inner  force  alone;  its  peculiar  efficiency 
requires  the  cooperation  of  the  brain,  the  nerves,  and 
the  muscles,  with  all  their  intricate  organization,  his- 
tory, and  inheritance. 

But  there  is  a  further  objection  to  the  possibility  objection 
of  an  interaction  of  mind  and  body  that  must  at  least  based  on  t 

-^  ^  conservatK 

be  touched  upon.     It  is,  that  such  interaction  would  of  energy, 
be  in  conflict  with  the  doctrine  of  the  conservation  of 
energy,  an  objection  frequently  urged  at  the  present 


288 


Experimental  Psychology- 


interaction 

escapes  this 
difficulty 


time.  It  is  at  bottom  very  like  the  one  we  have  just 
considered,  —  the  objection  from  cause  and  effect, — 
and  yet  it  differs  in  not  appealing  to  some  a  priori 
conception  of  causahty,  but  to  certain  generalizations 
of  science  based  upon  experiment.  The  thought  here 
is,  that  if  a  mere  mental  desire  or  voHtion  to  raise 
my  hand  can  start  a  brain-process  which  finally 
causes  my  hand  to  move,  this  would  mean  a  pro- 
duction of  energy  in  the  brain  without  any  compen- 
sating loss  of  physical  energy  elsewhere.  The  sum 
total  of  energy  in  the  physical  universe  would  thus 
be  altered  every  time  we  willed  to  move  our  body, 
and  the  present  belief  that  the  amount  of  energy  in 
the  world  is  constant  would  be  contradicted. 

Many  answers  have  been  given  to  this  objection 
of  which  I  shall  select  only  one,  given  by  the  late 
Professor  Solomons.^  For  every  unit  of  energy 
appearing  at  some  point  in  the  brain  as  a  result  of 
our  volition  (he  urged)  there  might  well  be  a  corre- 
sponding loss  at  some  neighboring  point.  In  other 
words,  the  fact  that  the  will  caused  the  brain-molecules 
to  change  their  condition  need  not  mean  a  change  in 
the  amount  of  energy  in  the  brain  or  in  the  universe. 
The  influence  of  the  mind  might  be,  not  to  add  to 
the  energy  of  the  brain  in  any  way,  but  simply  to 
redispose  it,  to  change  the  form  of  the  energy 
already  there,  to  determine  which  among  various 
forms  it  should  take,  just  as  we  might  determine 
whether  a  given  amount  of  energy  in  a  piece  of 
coal  should  take  the  form  of  light  or  of  heat  with- 

1  "  The  Alleged  Proof  of  Parallelism  from  the  Conservation  of 
Energy,"  Philosophical  Review^  Vol.  VIII,  p.  146. 


The  Connection  of  Mind  and  Body     289 

out  our  decision  making  any  difference  in  the  sum 
of  energy  involved. 

The  intercourse  of  mind  and  body  consequently 
need  not  mean  a  give-and-take  of  physical  energy, 
nor  are  we  required,  in  accepting  it,  to  give  up  the 
great  principles  of  our  present-day  science. 

Interaction  therefore  cannot  as  yet  be  ruled  out  and  remains 
of  court  and  the  decision  be  given  to  parallelism  be-  ^.^^J^  ^^^ema- 
cause  it  alone  is  left.  Certainly  either  of  them  is  at 
present  a  live  alternative,  with  the  future  looking 
perhaps  more  favorable  for  interaction.  But  even  in 
regard  to  this  there  are  difficulties,  in  that  we  cannot 
understand  how  the  interaction  takes  place.  And 
yet,  as  Lotze  has  pointed  out,  any  interaction  what- 
ever, even  between  physical  things,  is  in  the  end  a 
mystery.  So  that  the  difficulty  in  psycho-physical 
causation  is  not  a  special  and  peculiar  one.  One  must 
also  admit  that  it  is  perhaps  premature  to  say  just 
what  will  be  the  ultimate  solution  of  the  problem  under 
discussion.  We  are  still  too  much  in  the  dark  as  to  the 
details  both  of  physiology  and  of  psychology.  If  one  "Corre- 
has  caution  ingrained,  and  wishes  to  avoid  even  a  pro-  fo°Ihe^"^^ 
visional  decision  where  the  evidence  is  so  far  from  cautious, 
being  all  in,  it  might  therefore  seem  advisable  to  hold 
to  some  non-committal  doctrine  to  be  called,  perhaps, 
"  Correspondence,"  which  includes  only  what  practi- 
cally all  psychologists  would  accept.  Such  a  doctrine 
would  simply  affirm  an  intimate  connection  between 
mental  phenomena  and  the  brain-cortex,  so  that  occur- 
rences on  the  two  sides  correspond,  process  for 
process,  leaving  it  an  open  question  what  the  more 
exact   relation   between   the   occurrences   might   be. 


290 


Experimental  Psychology 


whether  of  interaction  or  of  parallelism,  or  of  some- 
thing perhaps  different  from  both.  Most  persons, 
however,  would  chafe  at  such  restraint,  and  would 
prefer  to  push  on,  even  at  the  risk  of  taking  the 
wrong  road. 


Philosophy 
and  the  pres- 
ent question. 


The  scientific 
problem  vs. 
the  meta- 
physical. 


And  now  a  closing  doubt  as  to  whether  in  all  this 
long  discussion  we  have  not,  after  all,  been  merely 
tilting  at  windmills,  and,  could  we  but  clear  up 
our  philosophic  vision,  the  whole  question  as  to  the 
relation  of  mind  and  body  might  not  seem  absurd. 
Could  not  those  who  believe  that  mind  and  matter 
are  essentially  one,  —  the  monists,  for  instance,  who 
hold  that  these  two  are  but  different  appearances  of 
some  underlying  reality ;  as  well  as  the  idealists  who 
feel  that  matter  is  but  a  projection  of  the  mind, — 
could  not  those  who  have  this  faith  turn  upon  us  and 
say  that,  from  their  philosophic  point  of  view,  the 
problem  of  parallelism  or  of  interaction  ceases  to 
exist ;  that  theirs  is  the  true  solution  of  the  difficulty 
because  it  makes  us  see  that  mind  and  matter  are 
essentially  one } 

It  is  doubtless  true  that  the  difficulty  as  to  parallel- 
ism or  interaction  appears  in  a  somewhat  different 
light  when  viewed  from  the  standpoint  of  philosophy. 
When  mind  is  taken  in  its  widest  sense  it  is,  so  far 
as  we  know,  all  inclusive ;  there  is  nothing  beyond, 
and  there  would  consequently  be  nothing  that  could 
be  either  parallel  or  interactive  with  mind.  In  this 
idealistic  view,  psychic  and  physical  phenomena  are 
seen  to  be  but  two  sets  of  occurrences  within  the 
larger  compass  of  mind.    But  however  satisfying  such 


The  Connection  of  Mind  and  Body     291 

an  outcome  may  be  to  our  philosophical  instincts, 
I  cannot  feel  that  it  really  solves  the  problem  with 
which  natural  science  is  engaged.  Even  if  Professor 
Ward  should  be  right  in  saying  that  the  brain  is  but 
part  of  "  experience  as  a  result  of  intersubjective  inter- 
course," while  psychic  phenomena  are  our  personal 
and  private  experience,  and  that  consequently  all  dual- 
ism between  brain  and  psychic  events  disappears,  yet 
the  old  problem  reappears  in  a  new  form.  The  two 
kinds  of  ''experience"  are  still  distinct,  and  each  has 
its  separate  occurrences,  and  we  have  still  to  decide 
what  the  natural-science  relation  between  these  differ- 
ent classes  of  events  may  be.  The  fact  that  they  are 
both  at  bottom  "experience,"  and  therefore  similar 
in  kind  and  origin,  does  not  decide  whether  the  two 
orders  of  events,  scientifically  speaking,  interact  or 
run  in  independent  courses.  It  is  a  simple  question 
of  fact  to  be  settled  in  exactly  the  same  way  as  it 
would  be  if  we  did  not  accept  the  idealistic  view. 
Neither  ideahsm  nor  any  other  metaphysical  concep- 
tion is,  in  itself,  an  answer  to  this  question.  As  well 
might  one  claim  that  every  query  as  to  what  has 
occurred  between  Briton  and  Boer  was  answered 
when  once  we  were  told  that  the  two  peoples  were 
cousins  by  blood. 

But  the  psychological  and  natural-science  problem  The  really 
which  we  have  been  considering  is,  after  all,  of  far  ^^g°[^'^f 
less  vital  interest  than  the  further  question  of   the 
relative  worth  and  permanence  of  the  mind.     The 
questions  that  were  asked  of  Socrates  on  that  morn- 
ing   when   he   drank   the    hemlock,    are    the    really 


292 


Experimental  Psychology- 


are  un- 
touched by 
psycho- 
physiology. 


Yet  mind 
is  not  sub- 
ordinate to 
matter. 


absorbing  ones  to  which  the  experimental  work  is 
always  leading  us,  but  to  which  it  can  of  itself  give 
no  answer.  Is  the  body  a  mere  garment  which  the 
soul  may  lay  aside  ?  Or  is  the  mind  like  the  har- 
mony which  comes  from  the  lyre  —  something  that 
must  of  necessity  cease  when  the  strings  are  loosed 
and  broken.? 

The  studies  of  this  chapter  are,  as  I  have  said, 
no  answer  to  these  deeper  problems.  The  scientific 
results  stop  short  of  affirming  the  supremacy  of 
spirit;  but  they  also,  quite  as  truly,  stop  short  of 
asserting  the  primacy  of  nerves.  The  experimental 
evidence  shows  dependence  and  superiority  on  both 
sides.  While  it  is  true  that  drugs  and  disease  can 
change  the  whole  tenor  of  one's  thoughts,  it  is  also 
true  that  will  and  belief  produce  radical  results  in  the 
physical  world.  The  effects  of  hypnotism  and  sug- 
gestion as  a  means  of  healing  illustrate  this,  not  to 
speak  of  the  purely  material  changes  that  have  been 
brought  about  by  the  mental  force  of  such  men  as 
Caesar  or  Cromwell.  We  must  not  feel,  then,  that 
the  experimental  evidence  favors  exclusively  the 
view  that  mental  states  are  caused  by  the  brain. 
Nor  must  we  misinterpret  the  fact  that,  in  organic 
evolution,  intelligence  may  be  regarded  as  a  varia- 
tion which  assists  the  organism  in  its  struggle  for 
existence.  The  fact  that  the  mind  is  useful  to  the 
body  does  not  prove  that  this  is  its  sole  function. 
The  carpenter  is  doubtless  of  service  to  his  plane 
and  saw;  he  sharpens  them  and  keeps  them  in  re- 
pair. So  the  mind  may  be  of  service  to  the  body, 
and  yet  the  body  be  but  an  instrument  of  the  mind 


The  Connection  of  Mind  and  Body     293 

—  something  to  which  the  mind  ministers,  in  order 
finally  to  reap  benefits  of  a  purely  spiritual  kind. 

The  practical  outcome  of  all  this  seems  to  me  to  The  ex- 
be  a  certain  toleration  and  sanity  in  regard  to  both  ^^^""is*^- 
aspects  of  the  world.     In  the  first  place,  it  leads  one 
to  be  suspicious  of  theorizers  who  speak  exclusively 
in  physical  terms.     It  has  become  almost  fashionable  Nerve-ceii 
to  translate,  not  only  psychological,  but  also  educa-  P^^^sogy- 
tional  matters  into  physiological  phrases.     Much  is 
said    nowadays    of   "  central "    processes ;    and    the 
child's  schooling  is  discussed  as  if  its  nerves  alone 
were  being  treated.     Social  reforms  are  to  be  brought 
about  by  suitable  foods  and  proper  ventilation ;  while 
crime,  as  well  as  genius,  is  described  as  a  kind  of 
cerebral   disease.      Such   one-sidedness   cannot  live 
long  when  once  the  facts  are  understood ;  but  it  is 
half  true,  and,  for  that  reason,  all  the  more  difficult 
to  dislodge. 

But  we  should  be  equally  suspicious  of  those  who  The  real  im- 
are  blind  to  the  important  place  the  body  has  in  our  onhTbody. 
life.  We  ought  to  strike  some  mean  between  those 
who  see  only  the  physical  part,  and  those  who  dis- 
regard it.  The  material  and  sensuous  world  is  not  an 
enemy  of  the  spirit ;  it  is  not  the  source  of  evil  and 
sin,  as  the  followers  of  Plato  would  maintain.  Evil 
has  its  root  in  mind  as  deeply  as  in  matter.  Viewed 
aright,  the  body  is  the  great  opportunity  for  the  mind ; 
it  is  its  means  of  expression ;  it  must  be  depended 
upon  in  all  cases  where  we  act  either  for  ourselves 
or  for  others.  We  must  learn  to  respect  it  more, 
but  to  respect  it  only  for  what  it  can  do  for  us  in  our 
higher  aims.     We  must  rid  ourselves  of  the  older 


294  Experimental  Psychology 

view  that  the  body  is  a  sign  of  finitude  and  defect, 
and  regard  it  as  a  servant  of  our  inner  life.  In  the 
Heaven  of  Dante  each  spirit  was  manifest  as  a  flame 
of  fire.  Each  had  its  radiant  body.  It  would  not 
seem  to  me  strange  if,  some  day,  there  should  be  less 
hesitation  in  regarding  embodiment  as  a  universal 
mark  of  mind  —  that  even  the  divine  mind  is  like  us 
in  this  respect.  But  quite  apart  from  such  a  specu- 
lation, it  is  certain  that  we  are  formed  after  a  divine 
pattern  in  this,  at  least,  that  there  must  be  some 
utterance,  or  revelation  of  our  acts  in  the  outer  world 
if  our  inner  life  itself  is  to  be  complete.  The  work 
of  the  physiologists  in  showing  how  each  inner  state 
has  its  appropriate  and  necessary  expression  in  the 
physical  world  would  thus  be  another  support  of 
Leibnitz's  doctrine,  that  each  of  us  is  a  repetition 
of  the  larger  world  in  miniature. 


CHAPTER  XV 

SPIRITUAL  IMPLICATIONS  OF  THE  EXPERI- 
MENTAL WORK 

The  larger  meaning  of  our  psychological  experi- 
ments is  the  special  subject  of  this  chapter.  And  yet 
to  some  extent  this  has  been  the  topic  of  every 
chapter  of  the  book.  The  distinct  purpose  has  been, 
not  alone  to  recount  the  particular  experiments,  with 
their  apparatus  and  results,  but  to  show  if  possible 
their  bearing  on  life. 

There  remain  some  questions,  however,  that  are  Laboratory 
connected  with  no  special  experiments,  nor  with  par-  andTh^^'^*^ 
ticular  results,  but  are  rather  suggested  by  the  work  worth  of  the 
as   a  whole,   by   the   general   experimental  attitude  ^°^' 
toward  the  mind.     This  attitude  has  more  than  once 
aroused  a  doubt  as  to  whether  the  mind  is  quite  as 
worthy  of   respect   after  it   has   been   subjected   to 
machinery  and   computations.     Does   not   the  very 
fact  that  the  mind  submits  to  such  treatment  imply 
that  it  is  on  a  lower  plane,  that  it  is  grosser,  than  we 
may  have  once  believed  ? 

We    are   now    to    consider   these   broader   conse-  xhepro- 
quences  of  the  laboratory  work :  how  it  is  affectins:  ^"5^7  °^  ^^" 

^  J  o    quiring  as 

our  belief  in  the  reality  and  the  worth  of  the  soul.     It  to  the  per- 
seems  entirely  suitable  to  take  account  of  such  things 
and  to  ask  ourselves  what  effect  certain  doctrines  will  truth. 

295 


sonal  conse- 
quences of 


I 


296  Experimental  Psychology- 

have  on  practice  or  on  belief.  There  are  those,  how- 
ever, who  decry  any  questions  of  the  kind.  And  cer- 
tainly we  should  all  feel  that  such  questions  were  out 
of  place  when  asked  as  an  immediate  test  and  before 
accepting  scientific  results.  But  some  would  go  to 
the  length  of  saying  that,  even  after  acceptance,  no 
honest  man  would  for  a  moment  ask  himself  what 
were  the  personal  consequences  of  a  doctrine;  his 
interest  would  be  confined  merely  to  whether  it  were 
true  or  false.  This  heroic  devotion  to  truth,  regard- 
less of  the  effect  the  truth  may  have,  would  be  more 
admirable,  however,  if  it  had  not  in  it  a  touch  of  fanat- 
icism. There  are  religious  and  moral  fanatics ;  there 
are  also  scientific  and  intellectual  fanatics  —  persons 
who  are  seized  by  this  single,  Umited  interest  and 
see  all  things  subordinated  to  it.  For,  after  all, 
knowledge  was  made  for  man,  and  not  man  for  knowl- 
edge ;  and  those  who  feel  that  truth  is  something 
ineffably  sacred,  and  that  in  its  presence  man  and  his 
interests  are  not  to  be  considered,  simply  commit  on 
a  grand  scale  the  old  fallacy  of  the  miser  who  ends 
by  worshipping  the  gold  which  at  first  he  valued  only 
for  what  it  would  bring. 

One  may  therefore  be  intellectually  honest,  willing 
to  look  the  truth  in  the  face,  and  yet  be  primarily 
interested  in  what  the  truth  has  in  store  for  him  and 
for  those  like  him. 
Are  the  ex-         A  friend  of   mine,  a  man  of  great   philosophical 
r"Td*^       acuteness,  is  doubtful  of  the  psychological  laboratory 
doubtful         because  he  believes  it  to  be  founded  on  questionable 
metaphysics?  nietaphysics.     He  thinks  that  every  one  who  experi- 
ments on  mind,  openly  or  tacitly  commits  himself  to 


I 


spiritual  Implications  297 

the  doctrine  of  parallelism,^  and  that  if  parallelism 
should  be  disproved,  all  this  work  would  be  undone. 
The  more  common  impression,  however,  is  that  the 
experimenters  here  must  of  necessity  be  materialists ; 
for  there  certainly  is  an  air  of  materiality  about  any 
study  whose  chief  engines  of  discovery  are  pendulums 
and  chronoscopes.  How  can  one  hope  to  investigate 
the  facts  of  mind  with  brass  instruments  unless  he  as- 
sumes that  the  facts  of  which  he  is  in  search  are  but 
a  subtle  form  of  material  things. 

But  the  conclusion  in  each  case  is  entirely  wrong.  The  exacter 
One  commits  himself  neither  to  parallelism  nor  to  ^^iJjj^ft^one 
materialism  nor  to  any  special  theory  of  the  relation  neither  to 

/••I  1  j.i.r  T  •  i.11        materialism 

of  mmd  and  matter  by  proceedmg  experimentally.  ^^^^^ 
Psychological  experiments  are  but  a  special  method  parallelism. 
of  making  observations,  and  there  is  no  more  meta- 
physics implied  in  them  than  in  ordinary  introspec- 
tion or  in  the  casual  observation  of  a  companion.  If 
you  were  to  conclude  that  your  friend,  on  some  occa- 
sion, was  embarrassed  because  he  blushed,  no  one 
would  feel  tempted  to  say  that  this  inference  of  yours 
impUed  that  you  were  a  materialist  or  a  parallelist. 
It  is  evident  that  your  conclusion  is  not  based  on  any 
particular  theory  of  the  connection  of  mind  and  body, 
but  is  drawn  from  the  common  observation  that 
blushing  and  embarrassment  often  go  together,  and 
that  you  are  reasonably  safe  in  concluding  that  in  this 
instance  the  one  is  a  sign  of  the  other.  But,  strangely 
enough,  if  instead  of  simply  looking  at  his  skin,  you 
take  a  record  by  means  of  a  plethysmograph,  you  are 
at  once  supposed  to  have  surrendered  to  a  metaphysical 

1  Cf.  p.  278. 


298  Experimental  Psychology- 

theory.     The  new  method,  however,  is  simply  a  re- 
finement of  observation,  and  the  user  of  instruments 
of  precision  need  have  no  different  philosophy  from 
one  who  only  uses  his  eyes  and  his  memory. 
No  more  is  Or,  to  take  another  illustration,  we  may  observe 

ilTordkil^"  that  one  person  can  learn  in  a  few  seconds  what 
observation,  another  Cannot  acquire  in  twice  the  period,  —  this 
without  prejudice  to  the  question  of  the  ultimate 
nature  of  mind.  But  if  instead  of  depending  on  my 
careless  impression  as  to  the  time  involved,  I  measure 
it  by  tuning-forks  and  smoked  paper  to  a  thousandth 
of  a  second,  I  am  not  thereby  giving  the  work  a  ma- 
terialistic or  parallelistic  or  any  other  bias.  The  fact 
that  the  subject  presses  an  electric  key  when  his 
mental  act  —  say,  of  arithmetic  —  is  complete,  hides 
no  more  dangerous  implications  than  if  he  were  to 
utter  the  answer  by  word  of  mouth.  Nor  is  it  assumed 
that  in  careful  experiments  of  this  kind,  the  printed 
number  presented  to  his  eye  causes  only  physical  pro- 
cesses, and  that  the  mental  action  is  "  parallel "  rather 
than  a  result  of  the  brain-action.  All  these  problems 
are  left  open,  to  be  decided  on  their  own  merits  by 
whatever  means  are  best  adapted  to  their  solution. 
We  do  not  have  to  assume  some  answer  to  them  in 
beginning  our  experimental  work. 

With  this  brief  consideration,  therefore,  I  shall  dis- 
miss this  first  question  by  saying  that  our  laboratory 
work  does  not  require  us  to  take  for  granted  that 
mental  phenomena  are  at  bottom  facts  of  matter, 
nor  do  we  have  to  assume  that  mind  and  body  are  con- 
nected in  some  particular  way.  Questions  like  these 
are  in  exactly  the  same  status,  as  far  as  bias  is  con- 


spiritual  Implications  299 

cerned,  as  if  we  confined  ourselves  to  simple  obser- 
vations of  our  own  mental  phenomena  and  those  of 
others.  The  laboratory  psychology  makes  no  strange 
assumptions ;  it  is  not  in  some  mysterious  way  a 
device  of  materialism,  or  of  something  equally  dubi- 
ous. It  is  simply  a  better  way  of  doing  what  men 
have  always  done  in  the  study  of  mind. 

We  may  therefore  pass  on  to  the  next  question,  as 
to  the  actual  effect  of  such  laboratory  studies  upon 
the  behef  in  the  existence  of  the  soul. 

The  new  psychology,  with   its   physiological  and  "Psychology 
laboratory   methods,   is  often  referred   to   as    "psy-  ^ourMs^a 
chology  without  a  soul."     Later  we  shall  see  that  justexpres- 
this  expression  is  half  untrue,  but  yet  it  does  seem  to  extent.^  ^°"^^ 
me  to  be  in  some  ways  an  excusable  designation  of 
the  work;  it  really  is,  to  some  extent,  "soulless,"  in 
the  sense  in  which  this  word  is  applied,  for  example, 
to  corporations :  it  goes  on  its  way  with  but  little 
heed  to  moral  or  religious  considerations.     All  those 
ways  of  looking  at  things  by  which  their  personal 
value  is  taken  into  account  are  sedulously  avoided. 
So  that  psychology  is,  indeed,  a  heartless,  unemo- 
tional way  of  regarding   even   our   most   cherished 
spiritual  affairs.    Just  as  the  physician  may  lose  sight 
of  the  person,  in  his  interest  in  the  "  case,"  so  psy- 
chology deals  with  the  facts  of  the  mind  in  a  cold, 
impersonal  way ;  it  is  interested  in  facts  rather  than 
in  duty  or  in  human  welfare. 

But  in  a  more  technical  sense  the  study  might  be  The  former 
called  **  psychology  without  a  soul."     As  a  friend  of  »ego.° 
mine  sat  one  day  in  his  garden,  a  pedler,  who  had 


300  Experimental  Psychology 

evidently  seen  better  days,  passed  in,  and  noticing 
that  he  was  reading  a  book  on  psychology,  asked 
whether  the  present-day  writings  of  the  kind  had 
much  to  say  about  the  "ego."  My  friend  had  to  con- 
fess that  the  ego  had  fallen  somewhat  into  neglect. 
In  the  older  days  of  psychology,  whenever  there  was 
an  especial  difficulty  that  had  to  be  overcome,  it  was 
easy  to  appeal  to  the  ego,  or  the  soul.  It  was  a  detis 
ex  machina^  called  in  when  the  situation  became  par- 
ticularly untoward.  And,  indeed,  does  it  not  seem 
a  valid  mode  of  explaining  a  mental  occurrence,  such 
as  an  act  of  will  or  the  recollection  of  an  event,  to 
say  that  the  mental  process  occurs  because  the  self 
is  there  to  produce  it  1 
The  nature  The  great  objection  to  introducing  the  self  as  a 
ex  Sanation  "i^^-ns  of  psychological  explanation  is,  that  the  ego 
is  not  a  particular  mental  process  among  other  pro- 
cesses ;  it  is  not  an  event  in  experience,  out  of  which 
other  events  may  flow.  The  older  attempts  to  em- 
ploy it  in  scientific  explanation  were  very  much 
like  accounting  for  the  climate  of  California  by  say- 
ing that  nature  causes  it.  The  statement  may  be 
true  enough,  but  it  is  not  enlightening.  What  we 
wish  to  know  is,  what  particular  features  of  nature 
bring  such  mildness  of  summer  and  winter;  and  if 
the  Japan  current  can  be  shown  to  be  responsible, 
the  state  of  things  becomes  relatively  intelligible. 
But  nature  is  a  collective  system  of  occurrences,  and 
to  use  it  as  a  principle  of  explanation  would  be  equiv- 
alent to  saying  that  "the  All"  does  some  particular 
thing.  We  do  not  understand  the  special  phenom- 
enon any  better  after  hearing  such  an  utterance  than 


spiritual  Implications  301 

before ;  we  are  still  in  the  dark  as  to  the  antecedents 
from  which  the  facts  in  which  we  are  interested 
spring. 

So  it  is  in  psychology.  The  reason  why  the  special-  The  soul  is 
ists  are  often  ready  to  accept  the  paradox  that  the  useiesfhere 
soul  may  here  be  left  out  of  account  is  simply 
because  it  is,  scientifically  speaking,  of  no  immediate 
assistance  in  explaining  mental  events.  The  soul  is 
not  a  particular  mental  phenomenon  among  other 
phenomena.  It  is,  rather,  the  personal  system  within 
which  my  particular  mental  events  occur.  It  bears 
the  same  relation  to  the  particular  facts  of  my 
mind  that  nature  does  to  the  events  of  the  physical 
world.  And  just  as  the  various  sciences,  while  all 
the  while  concerned  with  nature  and  her  ways  and 
history,  nevertheless,  in  a  sense  neglect  her,  in  that 
they  never  refer  to  her  as  the  cause  or  explanation 
of  particular  events ;  so  our  modern  psychology  is 
learning  to  proceed  without  the  soul.  Not  that  in  a  Yet  a  deeper 
further  study  one  finds  no  evidence  of  its  existence,  ne^^ecuhe°* 
nor  does  in  any  true  sense  neglect  it,  nor  ever  can  soul, 
neglect  it.  Every  new  fact  in  the  mental  life,  and 
every  new  context  that  is  revealed,  does  in  reality  add 
to  our  knowledge  of  the  soul.  But  the  psychologist 
has  rightly  recognized  that  his  work  must  be  to  seek 
for  precise  and  particular  causes  in  the  mental  realm, 
and  never  to  rest  satisfied  with  attributing  the  event 
broadly  to  the  ego,  or  self.  The  current  phrase,  "psy- 
chology without  a  soul,"  simply  means,  then,  that  in 
the  treatment  of  the  mental  world  after  the  manner 
of  natural  science,  the  mind  as  a  whole  is  not  to  be 
employed  as  an  explanation  of  particular  mental  occur- 


302      •        Experimental  Psychology 

rences ;  it  is  not  a  phenomenon  among  phenomena ; 
in  the  limited,  scientific  sense  of  the  word,  it  is  not 
the  cause  of  its  own  occurrences. 

But  if  not  a  But  men  are  influenced  by  the  phrases  they  em- 
cause^wh  pW»  ^^^  ^^^  mere  words  in  which  this  thought  is 
believe  in  the  clothed  will  probably  encourage  the  notion  that  the 
^°^  soul  is  something  in  which  the  enlightened  mind  no 

longer  feels  called  upon  to  believe.  To  say  that  in 
the  more  recent  treatment  of  psychology  there  is  no 
immediate  use  for  any  deeper  reality  than  our  desires 
and  ideas,  and  that  if  the  soul  exists,  it  certainly  is 
not  a  cause  in  the  scientific  sense,  sounds  not  unlike 
the  assertion  that  it  is  not  a  cause  in  any  sense  what- 
ever. And  this  would  be  equivalent  to  saying  that 
it  does  not  exist.  For  no  one  will  long  believe  in 
anything  that  is  not  causal  and  active.  The  sign  of 
reality  is  that  it  can  do  something.  When  it  ceases 
to  be  of  influence,  it  ceases  to  be.  So  that  it  is  im- 
portant that  we  keep  before  us  the  fact  that  the  soul, 
in  spite  of  its  disappearance  from  psychology,  has 
not  disappeared  from  the  earth.  It  is,  indeed,  the 
most  active  thing  with  which  we  have  any  direct 
acquaintance.  And  our  modern  psychology,  while 
waving  farewell  to  the  soul  with  one  hand,  is,  in 
truth,  earnestly  beckoning  it  back  with  the  other. 
The  modem  For,  in  the  first  place,  students  are  beginning  to 
view  IS  not  so  |^g   awarc   that   the   mind   can   never   be  treated  in 

soulless  as 

theoidasso-  its  fulucss  SO  loug  as  we  couccive  of  mental  phe- 
nomena too  closely  after  the  analogy  of  physical 
events.  From  the  time  of  Hume  and  Hartley,  even 
down  to  the  present  day,  there  has  been  a  school  of 


ciationism. 


spiritual  Implications  303 

psychologists  who  believed  that  they  could  adequately 
describe  the  mental  life  somewhat  after  the  manner 
of  our  present  nebular  hypothesis  in  astronomy. 
Just  as  the  prominent  celestial  bodies  are  due  to  the 
aggregation  of  numberless  particles  of  disseminated 
matter  called  star-dust,  so  the  mind  was  conceived  as 
beginning  in  a  kind  of  scattered  idea-dust  —  minute 
and  chaotic  psychic  elements,  or  sensations  —  which 
gradually  collected  into  more  or  less  stable  groups 
until  there  finally  emerged,  by  further  thickening  and 
more  complex  groupings,  an  orderly  system  of  expe- 
rience with  its  ideas,  its  emotions,  and  its  reasoned 
acts  of  will.  This  good  old  associationist  view  ought 
really  to  have  been  called  psychology  without  a  soul; 
for  the  most  real  things  in  the  mental  life,  according 
to  this  conception,  were  the  constituent  elements,  the 
primitive  sensations,  and  whatever  mind  there  was 
came  from  the  assembling  of  these  individual  sensa- 
tions. The  soul  was  simply  a  collective  term  for 
the  numberless  minute  impressions  which  came  and 
went,  no  man  could  say  whence  or  whither. 

It  is  not  difficult  to  appreciate  what  a  chance  affair  The  older 
the  mind  was,  according  to  this  view.     The  soul  had  ^^f  hostile  to 
no  inherent  power;    it  had  no  inherent  stability;  it  our  higher 
was  entirely  a  creature  of  circumstances.     Morality 
was  a  matter  of  custom;  immorality  was  not  to  be 
seriously  considered. 

The  essential  features  of  such  a  doctrine,  however.   Persons 
have  not  been  confined  to  the  psychologists.     Much  ^^^^f^^jy^ 
of  our  current  popular  thinking  runs  the  same  course,  unreal. 
The  influence  of  society  upon  the  individual  is  often 
represented  as  if,   surrounding  us  all,  there  were  a 


304 


Experimental  Psychology 


Mental  phe- 
nomena 
regarded  as 
acts  of 
persons. 


great  stratum  of  impersonal  thoughts,  a  mental  atmos- 
phere that  had  its  own  storms  and  sunshine.  From 
this  would  be  explained  the  common  impulses,  the 
passing  styles  of  thought,  the  "  movements  "  that 
pass  like  a  wind  over  the  minds  of  men.  Those 
who  believe  in  thought-transference  often  have  a 
similar  view ;  thoughts  seem  to  them  to  be  relatively 
separate  and  self-existent  things  that  can  literally 
pass  from  one  mind  to  another.  The  mind  is  viewed 
as  a  kind  of  receptacle  for  thoughts,  as  in  that 
classic  figure  where  each  of  us  is  likened  to  an  aviary, 
and  our  thoughts  to  imprisoned  birds.^  And  just  as 
the  birds  may  escape  from  one  man's  enclosure  to 
that  of  another,  or  perhaps  fly  about  and  be  possessed 
by  no  one  at  all ;  so  our  thoughts  are  pictured  as 
though  capable  of  existing  separate  from  the  mind, 
and  we  as  simply  their  temporary  assembly.  In 
Oriental  philosophy  there  is  a  kindred  belief.  The 
individual  is  but  a  drop,  separated,  for  the  time,  from 
the  mother  sea  of  impersonal  life  into  which,  in  the 
end,  he  is  to  return.  The  common  feature  in  all 
these  conceptions,  otherwise  so  different,  is  that  the 
person  is  less  enduring  and  important  than  the  con- 
stituents that  enter  into  him.  He  is  but  the  artificial 
form  which  they  assume.  He  is  but  a  temporary 
group,  or  product,  of  psychic  facts  that  can  quite  as 
well  exist  in  an  impersonal  way. 

One  may  truthfully  report,  I  think,  that  this  con- 
ception has  for  many  years  been  losing  ground  among 
psychologists.  The  ascendant  view,  and  the  one 
that  seems  to  me  by  far  the  more  convincing,  is  that 


1  TheceMuSf  Staph.,  197  et  seq. 


spiritual  Implications  305 

sensations  and  judgments  and  memories,  and  all 
things  else  in  our  mental  life,  are  to  be  conceived, 
not  as  self-complete  and  relatively  independent 
things,  but  as  acts  of  a  living  being.  The  analogy 
of  particles  of  matter  grouping  themselves  into 
objects  cannot  be  made  to  apply  to  mental  processes. 
The  changes  in  the  moral  world  are  not  a  mere 
reshuffling  of  older  entities.  The  mind  can  no  more 
be  constructed  out  of  small  pieces  of  ideas  than  the 
living  body  can  be  conceived  as  resulting  from  a 
gradual  assembling  of  scattered  heart-beats,  with, 
later,  a  stray  digestion  and  the  rest.  The  relative  The  soul  is 
standing  of  the  soul  and  its  sense-impressions  is  thus  o°s^/^°^"^ 
entirely  reversed.  The  mind  is  the  deeper  and  more  impressions, 
permanent  reality,  and  mental  phenomena  are  its 
ways  of  behavior.  It  has  power  and  activity  from 
within.  It  is  not  a  mere  creature  of  circumstances, 
—  not  a  mere  eddy  in  the  endless  stream  of  sensa- 
tions, —  it  is  an  agent,  a  person,  facing  the  world, 
and  acting  upon  it  with  will  and  intelligence.  In 
offering  this  conception  that  the  mind  is  an  active 
participant  in  the  world  of  events,  now  conquering 
and  now  for  a  moment  beaten  back,  but  all  the  while 
a  power  as  real  as  aught  we  know  —  in  presenting 
such  a  view  modern  psychology  is  by  no  means 
justly  to  be  called  psychology  without  a  soul.  Nor  Higher  and 
is  it  to  be  called  soulless  because  it  does  not  speak  of  cels^e^s^re 
some  spiritual  reality  separate  and  aloof  from  our  intimately 
common  life  of  mind  —  from  our  plans  and  disap- 
pointments, our  daily  joys  and  pains.  It  is  often 
popularly  thought  that  the  soul  is  separate  from  the 
mind ;  that  it  is  a  substance  in  which  are  lodged  the 

X 


3o6 


Experimental  Psychology- 


Persons  are 

the  elemental 
facts. 


more  dignified  attributes  of  the  spirit ;  its  conscience, 
for  instance,  and  its  ideals  —  what  we  sometimes  call 
our  spiritual  nature.  But  there  is  really  no  reason 
to  disjoin  the  higher  and  lower  life  in  this  way.  We 
do  not  need  a  soul  separate  from  our  everyday  mind, 
any  more  than  we  need  two  bodies,  —  one  reserved 
for  the  state  occasions  of  life.  Conscience  and  ideals 
must  be  willing  to  come  close  to  homely  things,  must 
live  in  touch  with  our  commonest  acts,  or  they  may 
as  well  be  wanting.  So  that  in  making  no  separation 
of  the  soul  from  our  most  familiar  processes,  psy- 
chology will  do  the  spiritual  life  no  harm. 

I  feel,  then,  that  as  far  as  the  reality  of  the  soul 
is  concerned,  the  new  psychology  is  in  advance  of 
the  old.  It  makes  the  mind  a  living,  a  personal, 
thing.  Every  thought  that  arises,  every  emotion  that 
stirs,  is  significant  only  as  part  of  the  larger  life  of  a 
personal  being.  Persons  are  the  elements  of  reality; 
they  are  not  products,  nor  drift.  The  mind  is  not  a 
mechanical  interplay  of  psychic  atoms ;  it  is  a  living 
whole. 


But  persons 
are  subject 
to  psycho- 
logical laws. 


Some  may  feel,  however,  that  while  modern  psy- 
chology is  thus  recognizing  the  reality  of  the  per- 
son, it  is  to  some  degree  undoing  this  good  work  by 
reducing  the  behavior  of  the  person,  as  far  as  possi- 
ble, to  law.  The  old  notion  of  the  "uniformity  of 
nature,"  which  has  been  so  helpful  in  investigating 
physical  things,  is  now  quite  generally  extended  so 
as  to  apply  to  the  mental  realm  as  well.  The  uni- 
formity of  mind,  in  the  sense  that  like  circumstances 
lead  to  like   results,   has   now  become   the   general 


spiritual  Implications  307 

principle  upon  which  the  experimental  work  in  psy- 
chology is  based.  And  this  uniformity  of  mind  is  Experi- 
not  just  taken  for  granted  and  there  left,  but  it  is,  deTcefoJ'" 
as  time  goes  on,  receiving  considerable  verification,  this. 
The  preceding  chapters  have  attempted  to  describe 
certain  discovered  regularities  of  this  kind  which 
seem  to  be  quite  as  constant  modes  of  mental  action 
as  are  the  laws  of  the  physical  world.  Thus  you 
may  recall  the  simple  instance  that  all  persons  note 
the  difference  between  things  more  readily  when  the 
facts  are  brought  to  the  mind  in  succession  than 
when  occurring  at  the  same  time ;  or  that  the  mind 
is  universally  subject  to  illusions,  due  to  certain 
habits  of  interpreting  our  impressions  of  sense. 
These  are  laws  of  mental  operation,  and  our  study 
of  mind  is  steadily  enlarging  the  area  within  which 
such  uniformity  of  action  is  observed.  The  more 
we  become  acquainted  with  ourselves,  the  more  of 
these  machine-like  regularities  we  discover;  until 
the  thought  is  forced  upon  us  that  this  constancy  of 
behavior  under  like  conditions  is  an  absolutely  uni- 
versal feature  of  mind,  and  that  where  we  fail  to  find 
it  we  must  simply  conclude,  not  that  it  does  not  there 
exist,  but  that  our  eyes  have  not  yet  become  sharp 
enough  to  detect  it.  We  must  therefore  ask  our-  Does  not  this 
selves  whether  resrularity  of  this  kind  in  our  mental  ^^^^^^]^^^ 

o  J  regularity  de- 

actions  does  not  make  personality  a  less  noble  thing,  tract  from 

and   especially   whether  it   does   not   endanger   our  J^o^h?  I 

belief  in  human  freedom  and  responsibility. 

To  many  persons,  and  perhaps  to  all  of  us  in  cer- 
tain moods,  a  view  like  this  where  uniformity  reigns 
is  cheerless  enough.    Life  seems  to  have  been  robbed 


3o8  Experimental  Psychology 

of  some  of  its  interest.  There  is  nothing  in  store  that 
is  not  somehow  prefigured  in  our  present  mental 
states.  A  touch  of  unromantic  calculability  under- 
neath all  seems  to  take  from  our  spiritual  dignity 
and  to  make  us  appear  to  play  a  puppet's  part  in  life. 
The  value  of  And  yet  I  cannot  feel  that  the  thought  of  pervasive 
life  does  not    j-eprularitv  should  in  itself  detract  from  the  charm  or 

depend  upon         »  -' 

novelty.  valuc  of  life.     One  may  lay  too  much  stress  on  the 

element  of  surprise.  It  is  undoubtedly  true  that  we 
are  quickened  by  meeting  the  unforeseen ;  but  our  at- 
tention and  interest  is  not  wholly  dependent  upon 
such  stimulants.  Home-coming,  or  the  intercourse 
with  old  friends,  is  attractive  out  of  all  proportion 
to  the  novelties  we  discover.  The  preference  of 
children  for  an  oft-repeated  tale  reveals  the  same 
trait.  They  are  so  familiar  with  its  course  that  they 
mark  the  sHghtest  departure  from  the  original  form, 
and  yet  they  will  have  the  old  story  rather  than  one 
where  much  is  new.  And  certainly  our  serious  moral 
interests  are  even  more  firmly  based  on  other  things 
than  novelty.  The  affection  which  the  mother  bears 
her  child  does  not  require  the  intellectual  spur  of  the 
unexpected ;  it  may  persist  even  in  a  heightened  de- 
gree where  the  child  has  met  some  check  in  its 
mental  growth,  and  where  all  hope  of  change  has 
finally  died  away.  Or  if  the  child  develops  in  the 
sound  way  in  which  the  mother  expects  he  will,  this 
does  not  hinder  her  attachment.  Those  who  pity 
God  because,  as  they  suppose,  he  sees  the  end  from 
the  beginning,  do  not  understand  the  psychological 
foundations  of  interest  and  love. 

The  ennui,  therefore,  with  which  some  anticipate 


spiritual  Implications  309 

a  life  unfolding  according  to  law,  is  but  a  feeling  of 
the  idle  hour.  The  train  of  events  looks  tiresome 
because  we  assume  toward  it,  for  the  time,  something 
of  the  novel-reader's  attitude.  But  in  actually  living 
it  we  drop  this  fine  intellectual  or  aesthetic  air,  and  it 
becomes  more  and  more  a  matter  of  moral  relations, 
a  matter  of  loyalty,  of  responsibility,  of  personal 
affection. 

The  fear  that  the  progress  of  life  according  to  strict  Yet  surprises 
rule  would  steal  its  charm  is  groundless,  moreover,  f"o^ghare 

^  '  '    m  store. 

not  alone  because,  as  I  have  tried  to  show,  the  inter- 
est in  living  does  not  depend  on  sudden  and  unex- 
pected turns,  but  because  in  the  very  nature  of 
things  surprises  are  sure  to  come.  The  natural  law 
of  the  mental  life  is,  after  all,  a  thing  infinitely  com- 
plex. Even  if  our  knowledge  of  it  were  many  times 
extended,  the  feeling  that  regularity  makes  life  dull 
and  tame  would  be  like  the  notion  that  one's  interest 
in  the  human  face  would  of  necessity  cease  because  he 
had  discovered  the  way  in  which  our  features  are 
always  arranged.  Back  of  the  simple  scheme  of  two 
eyes,  a  nose,  and  a  mouth,  are  the  endless  specific 
modes  in  which  this  formula  may  be  fulfilled.  No 
two  faces  alike,  and  yet  all  modelled  on  the  same 
plan. 

But  not  only  will  the  fulness  of  the  mental   life  Higher 
never  be  exhausted  by  our  rules,  since  the  ways  in  ^Hng  the"^^^^ 
which  the  simplest  scheme  or  law  may  be  embodied  unexpected. 
are  endless,  but  the  nature  of  mental  growth  is  such 
that  we  have  no  way  of  telling  what  many  of  its  laws 
will  be  until  the  slow  progress  of  events  brings  them 
actually  into  effect.      Most  of  our  natural   laws,  as 


310  Experimental  Psychology 

well  as  our  psychological  laws,  are  not,  for  us  at  least, 
like  Platonic  ideas,  existent  in  perfection  from  all 
eternity.  They  are  what  has  been  termed  "contin- 
gent truths  "  ;  they  are  simply  our  way  of  describing 
our  life  as  the  life  itself  unfolds.  And  this  growth  is 
always  taking  new  directions,  revealing  new  features 
that  could  never  have  been  anticipated  from  our  knowl- 
edge of  the  formulas  that  sufficed  for  the  earlier 
stage.  The  laws  that  are  sufficient  to  describe,  for 
instance,  the  behavior  of  fire  and  air  and  water  be- 
fore there  was  life  upon  the  earth,  give  no  hint,  so 
far  as  we  can  see,  of  the  wonders  of  vegetation.  And 
probably  we  might  fully  formulate  the  changes  of 
plants  without  their  laws  implying  that  consciousness 
would  ultimately  appear  upon  the  scene.  When  these 
higher  stages  are  reached,  we  see  that  they  rest  upon 
the  lower,  that  there  is  no  absolute  disconnection. 
And  yet,  along  with  the  continuity,  there  is  something 
entirely  new.  After  the  event,  we  can  see  that  the 
conditions  for  its  coming  have  been  in  long  prepara- 
tion, but  we  could  never  have  assuredly  foretold  its 
coming  from  a  natural-science  knowledge  of  the  ante- 
cedent facts.  The  preceding  events  are  apparently 
necessary  for  its  coming,  but  they  do  not  produce  it ; 
it  is,  after  all,  in  some  respects  a  gratuity,  an  act  of 
supererogation,  of  the  universe. 
Illustrations  The  inner  development  of  the  mind  itself  shows 
chic  fieid^"  similar  stadia  of  growth,  similar  incomings  of  higher 
functions,  which  the  simpler  forms  of  mental  life  had 
given  us  no  reason  to  expect.  The  feeling  of  musi- 
cal harmony  might  serve  as  an  illustration  of  what 
I  mean.     The  pleasure  we  take  in   certain  musical 


spiritual  Implications  311 

chords  is  more  than  the  mere  perception  of  the 
sounds  that  enter  into  the  chord;  it  is  even  more 
than  the  power  of  comparing  the  impressions  and 
of  appreciating  that  they  are  of  different  pitch ;  it  is 
more,  too,  than  the  sum  of  the  pleasures  we  get  from 
individual  notes.  It  is  an  absolutely  unique  experi- 
ence, a  unique  mode  of  appreciating  the  tones,  which, 
so  far  as  we  can  now  see,  the  mind  might  have  lacked 
through  all  eternity,  and  no  one  could  justly  have 
said  that  the  earlier  life  had  given  promise  of  some- 
thing which  the  later  facts  had  failed  to  fulfill.  Of 
a  similar  nature  is  memory  —  the  conscious  survey 
of  the  past,  —  as  well  as  the  pleasure  of  imagina- 
tion. They  slowly  and  silently  appear  in  the  history 
of  the  race ;  they  are  built,  in  the  closest  way,  upon 
the  earlier  mental  foundation,  but  they  are  not  neces- 
sarily implied  in  its  earhest  form.  Out  of  the  depths 
of  the  mind,  new  powers  are  thus  always  emerging. 
Until  they  are  awakened,  neither  apparatus  nor 
scrutiny  will  show  that  they  are  there.  When  we 
understand  our  life  more  fully,  therefore,  we  find  no 
ground  for  supposing  that  the  laws  of  the  present, 
or  even  of  any  future  time,  will  take  the  interest  from 
what  is  still  to  come.  There  seems  always  to  be 
something  held  in  reserve,  and  no  amount  of  science 
can  ever  take  from  the  world  the  element  of  wonder. 
It  never  will  become  as  a  tale  that  is  told. 

But  if  the  constant  presence  of  law  still  seem  in  Psycho- 
some  way  a  menace  to  our  power  and  responsibihty,  a^f^oV^^^ 
we  must  remember  that  laws  are  not  forces  externally  external 
compelling  us  to  behave  contrary  to  our  own  nature ; 
they  are  mere  descriptions,  mere  statements,  of  how 


312 


Experimental  Psychology 


They  are 
compatible 
with  human 
freedom. 


Are  these 
laws  subject 
to  amend- 
ment ? 


the  mind  actually  does  behave.  Definite  character 
always  presupposes  some  specific  mode,  or  law,  of  be- 
havior. Indeed  it  would  be  difficult  to  conceive  of 
a  personal  existence  of  any  kind  that  would  be 
lawless,  in  the  scientific  sense.  If,  then,  we  were 
to  suppose  free  beings  to  exist,  we  should  natu- 
rally expect  them  to  reveal  some  inner  law.  We 
should  expect  them  to  have  a  definite  nature,  to 
show  constancy  and  system,  and  to  act  with  refer- 
ence to  what  was  present  and  what  had  gone  before. 
When,  therefore,  our  observation  of  ourselves  actu- 
ally brings  out  what  these  definite  forms  of  action 
are,  we  certainly  cannot  use  these  discoveries  as 
evidence  against  the  reality  of  freedom,  with  which, 
in  truth,  they  so  well  accord.  Here  as  elsewhere, 
therefore,  law  and  liberty  are  compatible  and  even 
inseparable.  At  first  the  effect  of  psychology  is  to 
encourage  the  notion  that  everything  is  mechanical, 
and  that  no  place  is  left  for  personal  force  and  will. 
The  very  regularity  of  nature  revives  the  belief  in 
fate.  Further  insight,  however,  shows  that  we  do  not 
have  to  choose  between  persons  and  law,  but  that 
personality  itself  is  the  most  perfect  example  of  law. 
Our  instinctive  distrust  of  law,  however,  does  not 
spring  wholly  from  its  long  association  in  our  minds 
with  the  impersonal  powers  of  nature,  with  forces 
that  have  no  regard  for  the  sufferings  and  desires  of 
men.  In  part,  at  least,  it  may  arise  from  our  experi- 
ence with  human  governments.  No  political  consti- 
tution has  ever  been  devised  broad  and  elastic  enough 
to  suit  forever  the  character  of  a  changing  people. 
There  comes  a  time  when  a  violent  disruption  alone 


Spiritual  Implications  313 

can  bring  the  constitution  into  accord  with  the 
nation's  new  life.  But  when  we  turn  from  political 
government  to  the  constitution  of  the  world  of  things 
physical  and  mental,  it  seems  as  if  this  larger  order 
of  things  were  neither  subject  to  amendment  nor 
capable  of  change  by  revolution.  The  whole  seems 
fixed  beyond  our  utmost  power.  So  that  we  perhaps 
unconsciously  feel  that  rigidity  like  this  can  never 
give  lasting  satisfaction  to  a  living  and  growing 
mind. 

But,  as  I  have  tried  to  show,  this  fixity  can  easily  indications 
be  overstated  as  regards  the  inner  constitution  of  the  pos^s^^iiinr 
mind.  Its  laws  are,  to  some  extent,  like  those  of  a 
healthy  state,  subject  to  new  enactments  as  new  situ- 
ations arise.  And  probably  beyond  the  limits  of  our 
present  knowledge  there  are  conditions  that  are  even 
better  adapted  to  our  growth.  May  it  not  be  that 
death  itself  is  just  such  a  period  of  adjustment,  when 
there  come  into  effect  new  laws,  both  inner  and 
outer,  that  are  better  suited  to  the  altered  wants  of 
the  person.  Looked  at  from  every  side,  it  seems 
clear  that  natural  law  need  never  be  found  to  be  a 
check  upon  our  growth.  Especially  as  it  is  revealed 
in  psychology,  it  is  the  sign  and  evidence  of  the 
deeper  life  within. 

This  is  the  bearing  of  recent  psychology,  it  seems  The  general 
to  me,  on  the  reality  and  worth  of  the  soul.  These  psych"o1o°/y. 
great  doctrines  are  certainly  in  no  real  danger  from 
the  modern  scientific  treatment  of  mind.  Indirectly, 
the  work  ought  to  strengthen  our  confidence  in 
spiritual  things.  It  is,  itself,  a  sign  of  a  growing 
interest  in  the  mind,  and  will  react  and  stimulate  the 


3H 


Experimental  Psychology 


interest  from  which  it  springs.  It  is  already  assist- 
ing us  to  recover  from  that  almost  exclusive  attention 
that  has  been  given  for  so  many  years  to  the  parts 
of  nature  that  are  below  the  human  plane.  And  in 
the  end  it  will  be  clear  that  man  can  never  be 
understood  until  he  is  regarded  not  simply  as  a 
physical  fact,  nor  merely  as  a  group  of  psychological 
phenomena,  but  as  a  centre  and  source  of  activities  — 
as  an  underlying  reality  —  of  which  the  special  occur- 
rences with  which  our  laboratory  experiments  are 
busied  are  but  surface  and  outcrop. 


I 


INDEX 


The  following  abbreviations  are  used:  exp,,  exps.  for  experiment-al,  experiments; 
phen.  for  phenomenon,  phenomena;  psych,  for  psychology,  psychological-Iy. 
Other  abbreviations  are  self-explanatory. 


Abstractions,  deference  due,  231. 
Accuracy  of  mental  measurements: 

doubts  in  regard  to,  56;   may  be 

overvalued,  57. 
Activity:   as  test  of  the  real,  302;  of 

the  mind,  1 19-21,  163. 
Acts,  psych,  phen.  regarded  as,  71, 

304- 
Advertisements,  psych,  of,  217. 
.^neas,  expression  of   his  emotion. 

269. 
.Esthetics,  vs.  psych,  of  beauty,  227. 

See  also  Art ;  Beauty ;  Pleasure. 
Affection :  and  the  unexpected,  308  ; 

parental,  308. 
After-images  :     duration    of,    21-6, 

40-1 ;   of  color  and  motion,  97. 
Allen,  Grant,  246. 
Alliteration,  255. 
Alterations  of  personality,  as  evidence 

for  the  unconscious,  70,  75-9. 
Amendment  of  psych,  law,  312-13. 
Amiel,  morbid  introspection  of,  3. 
Analogy  between  brain  and  mind, 

misapplied,  80,  81. 
Anatomy :   of  sense-organs,  and  the 

space-threshold,    125;    of    brain, 

271-6. 
Angell,  F.,  172,  178. 
Angels,  their  memory,  ace.  to  Dante, 

198. 
Angles,  illusion  from  subdivision  of, 

152-3. 
Animals :  their  space-perception,  161 ; 

memory,  183,    190-1;   recognition 

and  dreams,  191-2. 


Aphasia,  273. 

A  priori  method,  163,  285. 

Arc,  illusion  of  interrupted  a.,  117. 

Aristotle :  and  the  "  New  Psychol- 
ogy," I ;  A.'s  illusion  and  its  con- 
verse, 103-4,  113;  concerning  seat 
of  consciousness,  271. 

Arithmetic,  mental :  its  effect  on  cir- 
culation, 266. 

Arm,  volume  of,  under  different 
conditions,  264-5. 

Art :  and  memory,  191 ;  philosophy 
vs.  psychology  of,  227;  requires 
more  than  unity  in  variety,  248; 
"flesh"  and  "spirit"  in,  249; 
Wagner's  place  in,  257;  Greek 
and  modern,  257;  of  pure  color, 
258-^0. 

Arts :  differentiation  of,  249-61 ;  di- 
vergence of  color  and  drawing 
in,  253-4;  auditory,  256;  visual, 
257-60. 

Asceticism,  opposed  by  modem 
psych.,  270. 

Association,  cerebral,  in  infant,  276. 

Association,  mental:  memory  and 
verbal  association,  29;  in  space- 
perception,  143 ;  hindered  by  in- 
tensity of  impressions,  255; 
importance  of,  274-5. 

Association-theory:  in  exp.  psych., 
6;  limitations  of,  102;  of  space, 
122;  and  the  soul,  302-4. 

Association- time  :  shortened  by  limit- 
ing the  range  of  association,  42; 
not  primarily  physiological,  59. 


315 


3i6 


Index 


Assumptions,  in  psych,  exps.,  296-9. 

Astronomers,  as  experimenters  in 
psych.,  7-8. 

Astronomy:  relative  accuracy  in  a. 
and  psych.,  57 ;  analogies  in  psych, 
drawn  from,  303. 

Athearn,  exps.  by,  215. 

Atmosphere,  mental,  304. 

Attention :  affected  by  subliminal 
stimuli,  90-1 ;  illusions  from  stress 
of,  98-102 ;  direction  of,  influences 
movements,  203-4;  and  color- 
preference,  230;  pulse  of,  233-6; 
in  linear  grace,  239-41. 

Automatic  writing  and  speech,  76-9. 

Automatograph,  205. 

Automaton,  the  body  as  an,  279. 

Ave  Maria,  in  Mosso's  exps.,  268. 

Aviary,  the  mind  as  an,  304. 

Background,  the  mental,  83,  87. 

Bacon,  Francis,  4. 

Bakewell,  vi. 

Baldwin,  J.  M.,  and  imitation,  199, 
206. 

"  Bar,"  in  imaginary  rhythm,  232. 

Bashkirtseff,  Marie,  3. 

Beatrice,  198. 

Beauty:  sense  of,  an  ultimate  fact, 
164;  aesthetics  vs.  psych,  of,  227; 
character  of  experimental  work  on, 
227-46,  260;  factors  in  enjoyment 
of,  247-8. 

Beethoven  :  Choral  Symphony,  61 ; 
Fifth  Symphony,  257 ;  Fate  at  the 
door,  258. 

Belief,  influence  of,  on  the  power  of 
the  individual,  210. 

Benefits  forgot,  193. 

Bentley,  172,  178. 

Berenson,  214. 

Berkeley:  in  the  history  of  exp. 
psych.,  4;  his  "  New  Theory,"  4-5, 
128-31 ;  surgeon's  exps.  to  test  his 
view,  s;  the  world  as  visual  lan- 
guage, 105. 

Berlioz,  his  descriptive  music,  257. 

Bertino,  exps.  on  the  brain  of,  266-8. 

Bessel,  and  personal  equation,  8. 


Binocular  depth,  135-7, 187. 

Birds:  vision,  137;  thoughts  likened 
to,  304. 

Blind-spot,  imaginative  fiUing-in  of, 
214. 

Blind,  the:  their  space  discrimina- 
tion, 45-7 ;  exps.  on,  after  surgical 
relief,  129-35,  ^44-5 !  ^s  living  in  a 
time-world,  139-40;  value  of  im- 
pressions for,  1 8 1-2 ;  interest  in  the 
voice,  182 ;  dreams,  182. 

Blood,  circulation  of,  under  diff. 
psych,   conditions,   264-8. 

Body,  the:  inference  from  early 
organization  of,  162;  responsive 
to  mental  states,  206;  affected 
by  imitation,  219-20;  not  a  clog 
upon  the  mind,  270;  seat  of 
consciousness  in,  271-5;  paral- 
lelism implies  uselessness  of, 
282;  real  importance  of,  293; 
connection  of  the  mind  and,  Ch. 
XIV,  262-94.  See  Mind  and 
Body. 

Bolton,  233. 

Books,  compared  with  personal  in- 
tercourse, 218-19. 

Boswell,  212. 

Bourdon,  125. 

Bradley,  53-4,  282. 

Brain :  cerebral  localization,  9, 
271-6;  motor  zone,  273;  sensory 
centres,  274 ;  cooperation  of  parts 
of,  275 ;  subliminal  stimuli,  79-81 ; 
Mosso's  exps.  on,  265-8;  seat  of 
the  soul,  271-3;  infant's,  275;  is 
not  mind,  277;  interaction  and 
parallelism  of  mind  and,  278-91. 
See  Mind  and  Body. 

Brand,  vi. 

Bridgman,  Laura,  brain  of,  274. 

British:  interest  in  psych.,  4;  view 
of  space-perception,  122. 

Broca,  and  brain  localization,  9, 
272-3. 

Brown,  125. 

Browning,  quoted,  235. 

Buddhism,  ref.  to,  66,  304. 

Bunnell,  exps.  on  blind,  46. 


Index 


317 


Cagliostro,  communications  osten- 
sibly from,  77. 

Carlyle,  68. 

Car-window  illusion,  102-3. 

Cataract,  exps.  after  operation  for 
congenital,  129-35,  144-5. 

Categorical  imperative,  163. 

Catholic  dogmas,  basis  of  certain, 
219. 

Cattell :  on  recognition  of  colors,  41 ; 
on  mental  measurements,  65. 

Causation  :  discovery  of,  the  purpose 
of  mental  measurements,  64;  in 
memory,  188 ;  objection  to  inter- 
action from  idea  of,  283-87  ;  Hume 
on,  286;  as  test  of  reality,  302.  See 
also  below. 

Cause  and  effect :  the  relative  dignity 
of  each,  277;  equivalence  of,  not 
axiomatic,  283-4. 

Cheselden's  case,  5,  129,  144-5. 

Chicago  Fair,  color  preferences  at, 
230. 

Childhood,  reference  of  events  to, 
185,  188. 

Children :  space-discrimination  of,  45 ; 
development  of  brain,  275-6;  their 
verses,  255;  "  pure  "  sensations  in, 
162;  value  of  child-study,  184; 
memory  in,  191 ;  learn  by  sugges- 
tion, 217-18,  and  by  imitation, 
222 ;  do  not  imitate  all  things  alike, 
223;  personal  differences  in,  shown 
by  what  they  learn  from  their  com- 
panions, 223;  color  preferences, 
229-30;  early  consciousness  dis- 
jointed, 276 ;  education  of,  as  treat- 
ment of  nerves,  293;  liking  for 
oft-told  tales,  308. 

Choral,  units  of  interest  in,  235. 

Choroiditis,  effect  of,  138. 

Chronometric  work,  37-43.  See  also 
Measurements,  mental. 

Church,  power  of,  219. 

Circulation  of  the  blood,  changes  in, 
264-8. 

Cognitio  vespertina,  tnatutina,  196. 

Color :  in  impressionist  painting,  249 ; 
and   differentiation  of  Fine  Arts, 


Ch.  XIII,  249-61;  sense  of,  un- 
stable, 250-1 ;  and  space,  per- 
sonal equation  in,  251 ;  rivalry  of 
c.  and  drawing  in  art,  253-4; 
vividness  of,  with  loss  of  meaning, 
254;  in  ancient  sculpture,  257; 
art  of  pure  c,  258-9.  See  also 
below. 

Color-blindness :  in  infancy,  250 ;  in 
margin  of  vision,  250;  total,  251. 

Color-contrast :  measurement  of,  43- 
5,  56-8,  61-2;  heightened  by  lack 
of  definiteness,  58. 

Colored  sounds,  252. 

Colors :  Goethe's  exps.  on,  7,  18  ; 
memory  for  series  of,  28-9 ;  exp. 
on  "  complication "  of  c.  and 
sounds,  99-100  ;  change  of,  due  to 
disturbance  of  recognition,  loi, 
254 ;  comparison  of,  175  ;  of  shad- 
ows, 43,  214;  preferences,  229-30  ; 
harmony  of,  243,  246-7. 

Comparison,  successive  vs.  simulta- 
neous, 175,  178. 

"  Complication  "  of  sound  and  color, 
99-100. 

Conduct  :  influence  of  recollections 
on,  overestimated,  193 ;  and  one's 
scale  of  values,  194-5. 

Conscience,  relation  of,  to  the  rest 
of  the  mind,  164,  306. 

Consciousness,  and  brain-cortex,  39- 
40,  123,  271-6,  289. 

Conservation  of  energy,  as  objection 
to  interaction  of  mind  and  body, 
287-8. 

Constructiveness,  seat  of,  273. 

Contagion,  mental,  218. 

"  Contingent  truths,"  310. 

Convolutions,  cerebral:  as  seat  of 
consciousness,  272;  third  frontal, 
273;  cooperation  of,  275.  See 
also  Brain. 

Correspondence  :  of  mind  and  body, 
162;  of  mental  and  cerebral  pro- 
cesses, 289. 

Cortex,  cerebral,  and  consciousness, 
39-40,  123,  271-6,  289.    See  Brain. 

Crime,  as  cerebral  disease,  293. 


3i8 


Index 


Cross,  Roman  and  Greek ;  aesthetics 

of,  244. 
Crow-bar  case,  272. 
"  Curve  "  of  forgetfulness,  168. 
Curves,  pleasure  in  :   eye-movement 

theory    of,     237;     exps.    showing 

source  of,  238-42. 
Custom :   as  a  source  of  illusions, 

102-5,  107 ;  r61e  of,  in  harmony  of 

senses,  151. 

Dante :  memory  of  angels,  198 ;  terza 
rima  of,  255  ;  appearance  of  blest, 
294. 

Darwin  and  Heraclitus,  i. 

"  Dead  time  "  in  reaction,  exps.,  39- 
41. 

Deaf,  the :  value  of  different  impres- 
sions for,  iBi;  dreams  of,  182; 
laughter  of,  202. 

Death  and  psych,  law,  313. 

Defeat,  suggestion  of,  unpleasant, 
240. 

Delirium,  images  in,  97. 

Delusion :  regarding  magnets  and 
insanity,  93 ;  and  illusion,  118. 

Democritus,  a  friend  of  sense,  249. 

Dependence,  personal,  and  inde- 
pendence, 221-2. 

Depravity,  intellectual,  and  illusions, 
115-6. 

Descartes,  and  seat  of  soul,  272. 

Deutschmann,  Christine,  dreams  of, 
182. 

Development :  place  of  memory  in 
mental,  188-198  ;  of  fine  arts,  255- 
60;  of  brain,  275-6. 

Differences,  imperceptible,  in  psych, 
may  be  real,  84-5.  See  Discrimi- 
nation. 

Direction :  sense  of  visual,  136 ; 
harmony  of  touch  and  sight  as 
regards,  145-9. 

Discords,  harmonies  and,  of  space- 
perception,  Ch.  VIII,  142-64.  See 
Music. 

Discrimination  :  Weber's  Law  of,  11 ; 
in  flicker  exp.,  25,  40-1;  spatial  d. 
measured,  45-7;  exps.  on,  as  evi- 


dence for  the  unconscious,  83-88 ; 
discriminative  to  absolute  thresh- 
old, 86. 

Disorder,  unpleasantness  of,  240. 

Dispositions,  psychic,  and  memory, 

74-5- 

Distance :  sense  of,  136 ;  the  blind, 
and  perspective,  140;  factors  in 
judgment  of,  186-^;  suggestion 
and,  214. 

Distinctness,  in  psych,  of  time,  185-7. 

Distortion,  heightening  of  color  by, 
loi,  254. 

Distortion,  in  memory :  distinguished 
from  blurring,  170;  reasons  for, 
only  partly  understood,  173. 

Divinity,  and  embodiment,  294. 

Divisions  in  psych.,  artificial,  119. 

Dixie,  recognition  of,  183. 

Dogs :  sight  vs.  smell,  183 ;  recogni- 
tion of  places,  191-2. 

Donaldson,  274. 

Drama,  music  and,  256-7. 

Drawing  vs.  color,  in  art,  253-4. 

Drawings  of  objects  seen  but  an 
instant,  177,  215. 

Dreams:  and  spontaneous  stimuH, 
96-7 ;  bearing  on  multi-personality, 
78 ;  cross-examination  in  court,  78 ; 
how  distinguished  from  reality,  113- 
14;  their  place  in  psych,  reality, 
115;  of  the  blind,  182;  of  the 
deaf,  182 ;  usually  not  reminiscent, 
191 ;  animals',  191 ;  children's,  191. 

Dress,  styles  of,  and  suggestion,  216. 

Drugs,  psych,  effect  of,  292. 

Dufour's  case,  130. 

Dunan,  and  the  visualists,  139-40. 

Dunlap,  vi ;  exps.  with  imperceptible 
shadows,  88-90. 


Ebbinghaus,  exps.  on  memory,  166- 

169. 
Education,  see  Children. 
Ego,  modern  neglect  of,  299-300. 
Elements,  psychic,  303. 
Ellipses,    preferred    proportions    in, 

244. 


Index 


3^9 


Emerson,  on  memory,  189. 

Emotion :  in  localizing  events  in 
time,  187-9;  expression  of,  263, 
268,  269.     See  also  Expression. 

Energy,  conservation  of,  as  objec- 
tion to  psycho-physical  interaction, 
287-8. 

Enjoyment,  see  Pleasure. 

Error  of  mental  measurement,  56-9. 

Euclidean  geometry,  space-illusion 
and,  152-7. 

Evidence,  scientific  attitude  toward, 
94. 

Evil:  fascination  of,  220;  has  its 
source  in  both  mind  and  body,  293. 

Evolution :  objection  to  parallelism 
from,  281;  relative  importance  of 
mind  and  body  in,  292.  See 
Development. 

Exactness,  in  psych,  measurement, 
57;  no  absolute,  in  any  scientific 
measurements,  57;  lack  of,  does 
not  prevent  induction,  57. 

Expectation,  in  harmonizing  touch 
and  sight,  149. 

Experience :  in  illusions,  98, 100, 102, 
106,  107;  involves  logical  circle, 
112;  is  its  own  criterion,  112-13; 
not  a  direct  impress  from  without, 
1 19-21 ;  place  of  space-element  in, 
159-64;  non-spatial  e.,  139-49;  in 
space-perception,  143;  in  harmony 
of  touch  and  sight,  149 ;  illusions, 
as  a  part  of,  156 ;  always  an  ideali- 
zation, 156-7 ;  yet  it  imperfectly 
conforms  to  both  real  and  ideal, 
159 ;  change  of,  in  memory,  169-79 ; 
is  less  sensuous  than  is  usually 
supposed,  176-9;  maximum  of 
clearness  in,  179;  requires  reten- 
tion, 190;  brain  and  mind  as  forms 
of,  291. 

Experiments,  psychological:  history 
of,  Ch.  I,  1-16;  motives  for  rise, 
1-4 ;  influence  of  British  empiri- 
cism, 4-6;  the  Germans  in,  7-16; 
of  astronomers,  7-8 ;  of  physiolo- 
gists, 8;  phrenology  and,  9;  We- 
ber's, lo-ii :    Fechner  to  Wundt, 


11-15;  Lotze  and  Leibnitz,  15-16; 
general  character  of,  Ch.  II,  17-32; 
relation  to  physiological  exps., 
17-27;  analysis  of  flicker  exp.  to 
show  distinction  betw.  physiologi- 
cal and  psych,  exps.,  21-26;  psych, 
exps.  and  higher  levels  of  mind, 
27-31;  apparently  sensuous  char- 
acter of,  explained,  29-30;  range 
of,  30 ;  place  in  psych,  as  a  whole, 
31-2,297-8;  ethical  doubts  aroused 
by,  295-314;  based  on  doubtful 
metaphysics,  296-8. 

Explanation,  scientific,  286-300. 

Exposures,  effect  of  short,  177,  215. 

Expression ,  physical,  of  mental  states : 
263-71 ;  subtlety  of,  264 ;  records 
ofvascular  changes,  264-8;  Mosso's 
exps.  on  living  brain,  266;  view  of, 
revolutionized,  269 ;  importance  of, 
for  emotion,  269;  expression  and 
mental  states  are  one  and  insepa- 
rable, 269 ;  gives  us  possession  of 
our  thoughts,  270;  necessity  for, 
294. 

Extension :  consciousness  of,  is  irre- 
ducible, 159 ;  as  inherent  in  sensa- 
tion, 160-3.    See  Space. 

"  Eye  and  ear  "  method,  8. 

Eyes:  effect  of  movements  of,  in 
perspective,  135-7;  feeling  while 
rolling,  238  ;  photographs  of  eye- 
movements,  238-42.  See  Color ; 
Sight. 

Fact  and  fancy,  not  distinguished  by 

vividness,  215.    See  Reality. 
Faculty :  independence  of,  disproved 

by  illusions,  loo-i ;  memory  not  a 

separate,  189. 
"  Faith  without  works,"  270. 
Fallacy,   logical,  illusion   and,   108- 

10;  in  all  sense-perception,  109-10. 
Fanaticism,  varieties  of,  296. 
Faraday,  on  table-tipping,  205. 
Fatigue :  in  linear  ugliness,  241 ;  in 

color-appreciation,  246. 
Fechner ;  and  Psycho-physical  Law, 

11-13;  influence,  13;  and  Miiller, 


320 


Index 


13;  contr?sted  with  Lotze,  15;  as- 
sumptions, 48;  exps.  on  aesthetic 
preference,  243-4. 

Ferrier,  9. 

Fillmore,  on  Indians'  recognition  of 
music,  133-4. 

Finger  tips  :  minimal  roughness  per- 
ceived by,  125 ;  blind  man's  feeling 
in,  135- 

Fish,  their  vision,  137. 

Flechsig:  on  cerebral  localization, 
274;  indebtedness  to,  274;  on 
order  of  development  of  senses, 
276. 

Flesh  vs.  spirit  in  art,  249.  See  Mind 
and  Body. 

Flicker-experiment  :  analysis  of, 
21-6;  seems  purely  physiological, 
21 ;  psych,  features  of,  22-6 ;  as 
instance  of  mental  chronometry, 
40-1. 

Flournoy,  exps.  on  Mile.  "Smith," 
76-8. 

Foot,  poetic  and  psych.,  233-6. 

Forgetfulness :  what  becomes  of  for- 
gotten ideas?  71;  rate  of,  166-9; 
explained,  180.    See  Memory. 

Form,  mental :  vs.  mental  matter,  162, 
231,248;  lacks  intensive  quantity, 
48 ;  in  perception,  is  from  us,  120 ; 
almost  absent  in  child,  276 ;  enjoy- 
ment of,  Ch.  XII,  227-48;  formal 
element  in  sensuous  enjoyment, 
231,  248 ;  elementary  forms,  in 
beauty,  232-45 ;  partisanship  re- 
garding, 249;  and  impressionism, 
250. 

Forms,  spatial:  memory  for  series 
of,  28-9 ;  recognition  of,  131-5. 

Franz's  case,  130,  134. 

Freedom,  and  psych,  law,  307-12. 

Frequency  of  light  sensations,  21-6. 

Friends,  enjoyment  of,  308. 

Frog,  hemisphereless,  279. 

Future,  interest  in  the,  311. 

Gall,  9,  272. 

Galton's  whistle,  exps.  with,  173. 

Genius :  and  imitation,  225 ;  relation 


of,  to  his  times,  225;  as  cerebral 
disease,  293. 
Geometry :  modern,  and  the  psych, 
of  space,  122,  123, 152-7 ;  Kant  on, 

Ghost,  popular  conception  of,  270. 

God,  foreknowledge  and  interest, 
308. 

Goethe's  experiments  on  color,  7, 18. 

Golden  Age,  psych,  of,  171. 

Golden  ratio :  in  rectangles,  243-4 ; 
in  musical  tones  and  time-divi- 
sions, 245 ;  why  pleasing,  247. 

Goltz,  9. 

Good  and  evil,  derived  from  others, 
221, 

Gottingen,  work  at,  13. 

Gracefulness,  linear,  exps.  on,  237- 
42. 

Habit,  mental:  influence  of,  19; 
profit  and  loss  from,  43;  and 
memory,  74-5 ;  and  physical,  dis- 
tinguished, 75;  in  harmonizing 
senses,  151. 

Hallucinations:  logic  of,  109;  of 
insane,  114;  reality  of,  115.  See 
Illusions. 

Hand :  space-perception  by  the,  138 ; 
tracings  by  the,  200-1. 

Hansen,  206. 

Harmony:  as  test  of  truth,  114-15; 
of  touch  and  sight  as  regards 
distance,  142-5,  direction,  145-9, 
and  size,  149-51;  mind  as,  292; 
pleasure  in  various  kinds  of,  241-5, 
310-11 ;  factors  in,  246-7. 

Hartley,  6,  302. 

Hartmann,  and  the  unconscious,  66. 

Hart's  exps.  on  literary  rhythm,  234-5. 

Harwood,  172,  178. 

Hearing :  vs.  understanding,  47,  213, 
275 ;  as  space  sense,  142 ;  memory 
for,  170-1,  173-4,  179-80,  181 ; 
recognition  by,  183;  cerebral 
localization  of,  274;  infant's,  275. 
See  Music;  Sound. 

Heart,  and  consciousness,  271. 

Hegel,  mentioned,  7 ;  on  quantity,  55. 


Index 


321 


H616ne  "  Smith,"  case  of,  76-8. 

Heller,  46. 

Helmholtz,  5,  9,  243. 

Heraclitus  and  Darwin,  i. 

Herbart,  15. 

Hermann's  "  Hand-book,"  9. 

Heubner's  case,  275. 

Hirschberg,  178. 

History:  distortion  in,  174;  clarifi- 
cation in,  178;  influence  of,  not 
conscious,  193. 

History  of  psych,  exps.  Ch.  I,  1-16. 

Hitschmann,  on  dreams  of  blind, 
182. 

Hobbes,  4. 

Hodgson's  exps.  on  Mrs.  Piper,  76. 

Hoffding,  and  the  unconscious,  81. 

Home-coming,  interest  in,  308. 

Home :  mentioned,  5 ;  his  case,  129, 

I44-S- 

Homer :  mentioned,  31 ;  on  mind 
and  body,  262. 

Horse's  recognition  of  places,  191-2. 

Howison:  indebtedness  to,  vi;  on 
quantity,  55. 

Hume :  4 ;  on  space,  122 ;  on  causa- 
tion, 286 ;  on  mind,  302. 

H)T)notism  :  and  impulsiveness,  208 ; 
and  other  normal  phen.,  210 ;  post- 
hypnotic suggestion,  211 ;  fear  of, 
220;  individuality  in,  224;  and 
the  unconscious,  75. 

Idea-dust,  303. 

Idealism,  and  mind  and  body,  290-1. 

Ideals :  in  reality,  157,  159 ;  and  the 
rest  of  mind,  306. 

Ideas :  are  acts,  not  substances,  71, 
305;  may  be  reenacted,  72;  not 
unconscious,  83 ;  are  highly  organ- 
ized, 83 ;  recollection  of,  vs.  return, 
165,  or  persistence,  190;  fading 
of,  168-9;  distortion  of,  169-74; 
during  forgetfulness,  71-169;  are 
unstable,  169 ;  are  motor,  206,  209 ; 
importance  of  antithetic,  207-8 ; 
enjoyment  of,  256;  possession  of, 
by  expression,  270;  mind  not 
made  of,  305. 
Y 


Illusion :  Zollner's,  53 ;  revolving 
spiral,  97;  weight-size,  98;  suc- 
cession of  sounds,  99 ;  Aristotle's, 
and  converse,  103-4;  Miinster- 
berg's,  116;  interrupted  arc,  117; 
subdivision  of  angles,  152-3;  par- 
allel lines,  153-4;  three  points, 
154 ;  of  shape  and  size,  154.  See 
below. 

Illusions :  and  their  significance,  Ch. 
VI,  95-121;  service  of,  95;  range 
and  classification,  96-106;  three 
groups  are  alike,  106;  always  in- 
volve misinterpretation,  106-7; 
inevitableness  of,  107;  how  dis- 
tinguished from  perception,  108- 
14,  157-8;  a  kind  of  reality,  114- 
15;  and  scepticism,  115;  not 
annulled  by  detection,  116-18;  in 
play  and  art,  118;  main  teaching 
of,  loi,  1 19-21 ;  spatial  i.  and  real 
space,  155-7. 

lima  S.,  case  of,  71. 

Image,  mental :  development  of,  177; 
imageless  memory,  190. 

Image,  retinal :  least  perceptible  dif- 
ference in,  125  ;  inversion  of,  and 
upright  vision,  143,  146-9;  why  not 
conscious  of,  143-5. 

Imaginary  rhythms,  preference 
among,  232. 

Imagination:  a  high  achievement, 
190 ;  imaginative  filling-in  of  blind- 
spot,  214;  a  gratuity,  311. 

Imitation  and  suggestion,  Ch.  XI, 
199-226;  and  hypnotism,  209;  in- 
voluntary i.,  200;  in  movements 
of  hand,  200-1 ;  with  and  without 
sensible  pattern,  202-3;  in  the 
schools,  218 ;  in  morality,  218 ;  in 
religion,  219;  sinister  aspect  of, 
220 ;  and  responsibility,  221-2 ;  in- 
separable from  originality,  222; 
individuality  in,  223-4;  "  the  sincer- 
est  flattery,"  225 ;  and  genius,  225 ; 
destroys  itself,  225 ;  enjoyment  of, 
230,  240 ;  in  music,  257 ;  in  paint- 
ing, 258. 

Immortality,  and  associationism,  303. 


322 


Index 


Imperceptible  differences :  in  sensa- 
tion, 26;  may  be  psych,  real,  84-5. 
See  below. 

Imperceptible  sensations :  affect  con- 
scious processes,  88-90.  See  Un- 
conscious. 

Impersonal  thoughts,  304.  See  Per- 
son. 

Impression,  see  Sensation. 

Impressionism  in  painting,  43,  249. 

Impulse :  and  hypnotism,  208 ;  in- 
sistent, 2II-I2;  Dr.  Johnson's 
case.  212. 

Indians'  recognition  of  music,  134. 

Individual :  has  a  test  of  reality,  158 ; 
not  absolutely  plastic,  223,  226; 
varying  influence  of,  224 ;  i.  char- 
acter in  imitating,  224;  both  imita- 
tor and  pattern,  225;  i.  and  society, 
221,  303-4.     See  Persons. 

Individualism,  and  modern  psych., 
221. 

Infants:  sensuous  element  in,  162; 
color  preferences  of,  229-30 ;  brain 
of,  275-6;  disjointed  consciousness 
of,  276.    See  Children. 

Inference,  in  perception  and  illusion, 
io8-ii. 

Insane :  delusion  regarding  magnets, 
93;  images  of,  97;  and  test  of 
reality,  114. 

Insistent  questions  and  impulses, 
211-12. 

Intellect:  and  illusion,  117;  in  ap- 
preciating time-order,  29,  188-9; 
growth  of,  and  imitation,  219;  in 
color  preference,  230;  rivalry  of 
sense  and,  in  the  arts,  249,  256 ;  in 
music,  257 ;  and  the  moral  relation, 
308-9;  in  hnear  grace,  239-40;  in 
symmetry,  241. 

Intensity:  measurement  of,  43-5; 
most  troublesome  of  mental  quan- 
tities, 48-9,  62,  64 ;  applies  only  to 
sensation  and  feeling,  48 ;  does  not 
imply  that  mental  phen.  are  com- 
pound, 48-9;  attempt  to  expel,  50; 
measurements  of,  suspicious,  60; 
units  of,  60;  subject  to  impercep- 


tible gradations,  86 ;  change  of,  in 
memory,  170-1 ;  memory  for,  180-1. 
See  Measurement ;  Quantity. 

Interaction  of  mind  and  brain:  vs. 
parallelism,  278  ;  and  idea  of  causa- 
tion, 283-7 ;  conservation  of  energy 
and,  287-9 ;  philosophy  and,  290-1. 

Interest:  an  ultimate  fact,  164; 
rhythm  of,  in  verse,  233-5;  i^^ 
music,  235;  novelty  vs.,  308;  in 
future,  311. 

Interplay  of  faculties,  119-21. 

Interpretation :  fixity  of,  102-5 1  ^^ 
perception,  104 ;  in  illusion,  106. 

Introspection :  afundamental  method, 
1-2,  31 ;  difficulties  of,  2-4 ;  and 
exper.  method,  17-18,  31 ;  and  the 
unconscious,  66-7;  evidence  of, 
not  final,  86;  as  retrospect,  175; 
value  of,  277. 

Inversion :  hinders  recognition,  133 ; 
of  retinal  image,  and  upright  vision, 
143,  146-7. 

James,  Wm. :  20;  and  the  uncon- 
scious, 67,  93-4;  on  voluminous- 
ness  of  sensations,  160-3 1  his  "  Will 
to  Believe,"  211. 

Jastrow :  on  involuntary  movements, 
205 ;  on  color  preferences,  230. 

Jelly-fish,  its  fireedom  from  illusions, 
108. 

Jenning's  exps.  on  protozoa,  161. 

Job,  poetry  of,  255. 

Johnson,    Dr.,   insistent  impulse  of, 

2X2. 

Judgment:  affected  by  imperceptible 
impressions,  88-90;  moral  place 
of,  164;  influenced  by  suggestion, 
217-19;  is  a  personal  act,  305. 
See  Intellect. 

Kant:  on  psych,  quantity,  34;  on 
space,  122;  on  illusions,  155;  il- 
lusions and  his  doctrine  of  geome- 
try, iSS-7- 

Kennedy,  171. 

Knowledge :  criteria  of,  and  the  un- 
conscious, 93-4 ;  does  not  destroy 


Index 


3^3 


sense  illusion,  117-18;  aided  by  de- 
ception, 121 ;  critical,  vs.  memory, 
195-7 ;  relation  of,  to  man,  296. 
Krafft-Ebing :   case  of  lima  S.,  71 ; 
on  suggestion,  212-13. 

Lady  of  Shalott,  and  illusions,  120. 

Landscape:  contrast-colors  in,  43, 
58 ;  viewed  abnormally,  loi. 

Language :  outer  world  as,  105 ;  and 
thought,  217. 

Laughter  of  mutes,  202. 

Laus  temporis  acti,  171. 

Law :  knowledge  of,  in  memory, 
187-8 ;  knowledge  of,  vs.  memory, 
195-6. 

Laws,  psych. :  all  persons  subject 
to,  306-7  ;  and  human  worth,  307 ; 
and  prophecy,  309-10  ;  as  "  con- 
tingent truths,"  310 ;  and  responsi- 
bility, 311-12;  amendment  of,  312- 

13- 

Lehmann,  206. 

Leibnitz:  and  the  new  psychology, 
7,  16 ;  and  the  "  infinitely  little," 
68-9;  and  the  unconscious,  68-9, 
80-1, 82-91 ;  individualism  of,  221 ; 
and  psych,  of  expression,  294. 

Leipzig,  psych,  work  at,  14-15. 

Lenses,  reverting,  exps.  with,  146-7. 

"  Leopold,"  77. 

Letters,  memory  for  series  of,  28-9. 

Leuba,  173. 

Life,  value  of,  and  novelties,  308. 

Lines:  pleasure  in,  237-41;  pre- 
ferred divisions  of,  244;  vs.  color, 
in  art,  250. 

Localization,  cerebral,  of  mental 
functions,  9,  271-6. 

Localization,  conscious :  of  impres- 
sions, 123-5 ;  finer  than  nerve 
differences,  126-7;  ^^d  ocular 
paralysis,  135-6;  and  retinal  dis- 
turbance, 138 ;  vision  vs.  touch, 
142-9 ;  in  time,  185-9. 

Local  signs,  124-7. 

Locke:  and  exp.  psych.,  4;  and 
psych,  of  space,  122;  Molyneux's 
query,  128. 


Logarithmic  law,  Fechner's,  12. 

Logic :  and  illusions,  108-11 ;  in 
time-judgments,  188-9. 

Lotze :  his  mind,  15  ;  "  Medicinische 
Psychologic,"  15;  as  a  physiol- 
ogist, 20;  on  impersonal  experi- 
ence, 68  ;  on  interaction,  289. 

Lyric  temper,  the,  255. 

Magnetism  and  vagaries,  93. 

Man  vs.  woman,  color  preferences 
of,  230. 

"  Man  of  one  idea,"  and  association- 
time,  43. 

Mars,  communications  ostensibly 
from,  j7. 

Masterpieces  of  art,  why  exps.  neg- 
lect, 228. 

Materialism,  and  psych,  exps.,  297-9. 

Materia  prima,  48,  231. 

Mathematics :  and  psych,  of  space, 
122-3 ;  validity  of,  152-7 ;  pleasure 
and,  243-6.  See  Measurements, 
mental;  Quantity. 

Matter  t/j.  form,  distinction  approved, 
231.    See  Form,  mental. 

Matter  vs.  Mind,  see  Mind  and 
Body. 

Maudsley,  3. 

Measure,  poetic,  and  rhythm  of 
attention,  233-6. 

Measurements,  mental:  their  pos- 
sibility, Ch.  Ill,  33-65  ;  importance 
of,  33 ;  aim  of,  37,  64 ;  examples  of, 
37-47;  apparatus  and  methods  of 
time  measurements,  37-43;  of  in- 
tensity, 43-5 ;  of  space-discrimina- 
tion, 45-7;  objections  10,34-5,47- 
65;  is  mind  quantitative?  47-56; 
vs.  physical,  56-7,  59 ;  error  of,  58, 
59 ;  doubt  about  units  of,  60-3. 

Mediumistic  phenomena,  as  evidence 
for  unconscious  ideas,  76-9. 

Memory:  for  series  of  colors  or 
forms,  28-9;  as  evidence  for  un- 
conscious, 70-6;  does  not  imply 
preservation  of  ideas,  70-4 ;  moral 
place  of,  164,  193;  and  influence 
of  time,  Ch.  IX,  165-184 ;  vs.  mere 


3^4 


Index 


return  of  idea,  165;  analysis  of, 
165-6,  190;  field  of  exps.  on,  166; 
Ebbinghaus's  exps.,  166-9;  during 
short  intervals,  169,  178 ;  both  blurs 
and  distorts,  169-74;  for  different 
sense-materials,  170-1,  179-84;  for 
forms,  171;  memory-image,  172; 
clarification  in,  174-9;  corporate, 
174,  196;  understanding  in,  176; 
good  m.,  179;  utility  in,  180-1 ; 
temporal  signs,  185-9;  ^•'^d  the 
muses,  191 ;  in  personal  develop- 
ment and  identity,  189-94;  ^•^• 
intelligent  reproduction,  195-7 ;  is  a 
makeshift,  198 ;  of  angels,  198;  mem- 
ories as  acts,  305 ;  a  gratuity,  311, 

Metaphysics:  relation  to  psych.,  4; 
German  weariness  of,  7 ;  and  psych, 
methods,  19 ;  and  psych,  of  space, 
163-4;  ^"d  mental  measurements, 
35 ;  definition  of  the  soul,  36,  271 ; 
and  relation  of  mind  and  body, 
290-1 ;  not  assumed  in  psych,  exps., 
296-9. 

Method,  "  eye  and  ear,"  8. 

Method,  in  psych. :  introspective,  1-4, 
17-18,  31,  86,  277  (see  Introspec- 
tion) ;  objective,  4,  31 ;  physiolog- 
ical, 276-7;  experimental,  1-16, 
17-34,  296-9.  See  Experiments, 
psychological. 

Metre :  poetic,  233-5  >  as  affected  by 
mood  and  age,  255. 

Meumann,  268. 

Michelangelo,  254. 

Mill,  James,  6. 

Mill,  John  Stuart,  6. 

Mind :  subject  to  experiment,  17  (see 
Experiments,  psychological) ;  unity 
of,  119;  activity  of,  71,  119-21, 
163,  304;  seems  in  presence  of  ob- 
ject, 123 ;  organized  from  start, 
162;  uselessness  of,  282;  views 
world  indirectly,  123 ;  worth  of,  in 
light  of  exps.,  295 ;  as  analogous 
to  physical  things,  302-3  ;  and  soul, 
305-6 ;  and  body,  see  below. 

Mind  and  body :  connection  of,  Ch. 
XIV,  262-94;   undistinguished  in 


early  thought,  262;  physical  ex- 
pression of  mental  states,  263-71 
(see  Expression) ;  essential  con- 
nection between,  270 ;  disembodied 
mind,  270 ;  interaction  and  paral- 
lehsm,  278-91 ;  more  absorbing 
questions,  291-4 ;  conclusion,  292- 
4 ;  character  of  union  not  assumed 
in  psych,  exps.  296-8. 

Mind-reading,  and  involuntary  move- 
ments, 205. 

Minimum  visibile,  124-5.  See  Space- 
perception. 

Mirrors,  projecting,  exps.  with,  147-9. 

Mob,  action  of,  and  suggestion,  217. 

Models  of  number-forms,  253. 

Molyneux's  query,  128. 

Monday,  symbol  for,  252. 

Monism :  and  psychological  quan- 
tity, 55 ;  and  relation  of  mind  and 
body,  290-1. 

Montague,  vi. 

Moral  life,  the :  place  of  memory  in, 
192-5 ;  and  imitation,  218 ;  without 
a  soul,  299;  and  associationisrn, 
303 ;  and  intellect,  308-9. 

Mosso,  exps.  on  vascular  reactions, 
265-8. 

Movement:  in  space-perception,  5-6, 
135-41 ;  of  the  hand,  200-2 ;  sway- 
ing of  body,  203-4 ;  attention  and, 
203-5;  involuntary  m.  and  the 
occult,  205 ;  passage  of  ideas  into, 
206,  269 ;  circulatory,  264-8 ;  motor 
zone,  273.    See  Muscles. 

Miiller,  G.  E.,  13. 

Mviller-Lyer  illusion,  89. 

Munk,  274. 

Miinsterberg's  illusion,  116. 

Muscles :  in  space-perception,  5-6 ; 
135-8;  and  psych,  intensity,  50;  in 
Ebbinghaus's  exps.  on  memory, 
168;  memory  for  impressions  from, 
179-81 ;  muscle-reading,  205 ;  mus- 
cular theory  of  visual  pleasure,  237- 
42 ;  cerebral  localization,  273-4. 

Music:  Indians'  recognition  of,  134; 
disproves  a  theory  of  space,  159- 
60;   defects  in  recognition  of,  183; 


Index 


325 


pure  tones  in,  230 ;  units  of  interest 
in,  235 ;  pleasure  in  harmony,  243, 
246-7,  310-11 ;  and  mathematics, 
245 ;  operatic,  256 ;  separation  of 
poetry  from,  256-7;  instrumental, 
257;  its  freedom  from  imitative 
restrictions,  258  ;  "  music  "  of  color, 
259-60. 

Mutes,  laughter  of,  202. 

Mysticism :  as  escape  from  psychic 
quantity,  55;  treats  space  lightly, 
164 ;  of  number,  246. 

Negative,  photographic,  and  dis- 
turbed recognition,  132-3. 

Nerves:  in  reaction,  39-40;  nerve- 
differences  and  space-discrimina- 
tion, 125-7 ;  equivalence  of  neural 
and  psychic  processes,  285  ;  psych., 
and  primacy  of,  292;  nerve-cell 
pedagogy,  293. 

"  New  Theory  of  Vision,"  Berkeley's, 
4,  128. 

Nirvana,  66. 

Noble,    exps.    on    literary    rhythm, 

234-S- 

Novelty,  not  essential  to  value,  308. 

Number:  the  most  pervasive  of 
psych,  quantities,  54-6 ;  mysticism 
of,  246;  number-forms,  253.  See 
Measurements,  mental;  Quantity. 

Objective  methods,  4,  31. 

Observation,  and  psych,  exp.,  297-8. 

Observatories,  psych,  in,  7-8. 

Omahas'  recognition  of  music,  134. 

Opera,  256. 

Order:  mind  craves,  232;  pleasure 
in,  240-1. 

Organic  sensations,  cerebral  localiza- 
tion of,  274. 

Organization :  mind  probably  pos- 
sesses, from  start,  162;  of  expe- 
rience need  not  be  spatial,  162. 

Oriental  viev^^:  of  the  unconscious, 
66 ;  of  personality,  304. 

Originality:  the  basis  of  imitation, 
222-6;   induced  by  others,  223-6. 

Ostwald,  286. 


Oyster,  its  freedom  from  illusions, 
108. 

Pain,  organic  changes  connected 
with,  268. 

Painting:  colors  in  old,  230;  color 
in  impressionist,  43,  249;  rivalry 
of  color  and  form  in,  253-4 ;  imita- 
tion in,  258. 

Parallel  lines,  illusions  of,  53,  153-4. 

Parallelism,  psycho-physical :  mean- 
ing of,  278 ;  and  reflex  action,  279; 
the  crux  of,  280 ;  extravagance  of, 
281,  284  ;  vs.  evolution,  281 ; 
means  mutual  uselessness  of  mind 
and  body,  282;  and  philosophy, 
290-1 ;  not  necessary  for  psych, 
exps.,  297-9. 

Paralysis  :  of  ocular  muscles,  135-6 ; 
and  brain-lesions,  273-4. 

Paramecia,  exps.  on,  161. 

Passivity,  of  mind,  apparent,  119-21. 

Paul,  St.,  opposition  to  the  "  flesh," 
249. 

Pearson,  K.,  284. 

Pedagogy,  nerve-cell,  293. 

Perception :  and  illusions,  104-5, 
108 ;  involves  fallacy,  109-10 ;  min- 
gles good  and  evil,  n6;  Plato  on, 
119-20;  development  of,  176-8; 
and  parallelism,  280. 

Personal  equation,  8,  38-43. 

Personality:  alterations  of,  70-1, 
75-6 ;  dream-personalities  and 
mediumship,  78 ;  Oriental  view  of, 
304.    See  below. 

Persons:  memory,  and  identity  of, 
192-4;  vs.  books,  218-9;  diff.  of, 
regarding  color  and  form,  251; 
and  truth,  295-6 ;  relation  to  psych, 
phen.,  304-6;  are  the  elemental 
realities,  306 ;  psych,  law  and  value 
of,  306-12. 

Perspective:  motor  factor  in,  136-7; 
and  the  blind,  140. 

Pessimism,  and  the  unconscious,  66. 

Phenomena,  mental :  cause  of,  277, 
280,  287,  300-1 ;  are  not  the  mind, 
304-6,  314. 


326 


Index 


"  Philosophical  Transactions,"  5. 

Philosophische  Studien,  15. 

Philosophy,  and  psycho-physical  the- 
ories, 290-1.    See  Metaphysics. 

"  Phinuit,"  76. 

Photography  :  of  eye-movements, 
238-42 ;  action  of  mind  compared 
to,  287. 

Phrenology,  9,  272-5. 

Physics,  vs.  psych.,  56-7. 

"  Physiological  Optics,"  Helmholtz's, 

9- 

' '  Physiological  Psychology,' '  Wundt's , 
14. 

Physiologists :  influence  upon  psych., 
8 ;  why  pioneers,  17 ;  attitude  tow- 
ard mind,  277.    See  below. 

Physiology:  no  mastery  of  psych, 
without,  18 ;  are  psych,  exps.  but  p. 
in  disguise  ?  20 ;  psych,  method  in, 
22 ;  value  for  psych.,  276-7 ;  physi- 
ological antecedents  to  every  psych, 
event,  287;  partiality  toward,  293. 

Pierce,  142. 

Pineal  gland,  and  the  soul,  271-2. 

Piper,  Mrs.,  automatisms  of,  76. 

Pitch,  memory  for,  173. 

Platner:  on  memory,  72;  visualist, 
139-40. 

Plato:  unhappiness  of  tyrants,  35; 
sense-perception,  119-20 ;  the  sense- 
world,  249;  mind  and  body,  270; 
evil,  293 ;  aviary,  304. 

Pleasure:  in  sensations  and  their 
forms,  Ch.  XII,  227-48;  causes  of, 
in  beauty,  247-8;  in  masterpieces 
of  art,  228 ;  color  preference,  229- 
30;  in  tones,  230-1 ;  in  elementary 
forms,  232-45;  rhythm,  232-6; 
curves,  237-40 ;  in  symmetry,  241 ; 
formal  and  intellectual  vs.  sensu- 
ous, 237-42,  254 ;  in  harmony,  243, 
310-11;  in  proportion,  243-4;  in 
number,  244-6;  color  vs.  drawing, 
253 ;  metrical  effects,  255  ;  and  dif- 
ferentiation of  arts,  256;  modern 
vs.  Greek  attitude  toward  colorless 
form,  257;  organic  changes  with,  268. 

Plethysmograph,  264. 


Pluralism,  and  psych,  quantity,  55. 
See  Persons. 

Podmore,  92. 

Poetry :  rhythm  of,  and  of  attention, 
233-6;  auditory  element  in,  255; 
vs.  music,  256. 

Points,  illusion  of  three,  154. 

Polonius,  as  suggestible,  216. 

Professors,  why  not  abolished,  218. 

Projection,  of  objects,  143-5. 

Proportion,  pleasure  in,  243-4. 

Protozoan,  psych,  of,  161-2. 

Psalms,  255,  271. 

Pseudoscope,  136,  140. 

"  Psychical  research,"  66,  76-9. 

Psychologists'  attitude  toward  brain 
and  mind,  276,  277-8.     See  below. 

Psychology :  "  New,"  began  in 
Greece,  1;  its  slow  progress,  3; 
and  metaphysics,  4,  19;  indebted- 
ness to  physiology,  18,  276-7 ;  and 
the  unconscious,  66-7,  93-4;  its 
divisions  artificial,  119;  "without 
a  soul,"  299-306 ;  and  spiritual  in- 
terests, 299-313.  See  Experiments, 
psychological ;  Method,  in  psych. 

Psychometry,  37.  See  Measure- 
ments, mental. 

Psycho-physics:  11-13;  relation  of 
mind  and  body,  Ch.  XIV,  262-94. 

Pulpit,  why  not  abolished,  218. 

Pulse,  of  consciousness,  and  aes- 
thetic pleasure,  233-6. 

Pulse,  physiological,  changes  in, 
264-8. 

Pythagoras,  remnants  of  his  mysti- 
cism, 246. 

Quantity :  importance  in  psych.,  33 ; 
applicable  to  mind,  47-56;  inten- 
sive, most  troublesome  in  psych., 
48-51 ;  spatial,  not  usually  admitted, 
but  should  be,  51-3 ;  temporal,  may 
be  neglected,  but  not  by  psychol- 
ogists, 54;  numerical,  pewades 
mind,  54-6;  change  of,  in  mem- 
ory, 170-1 ;  quantitative  correlation 
of  mental  and  physical  phen.,  283- 
6.    See  Measurements,  mental. 


Index 


327 


Questions,  insistent,  211-12. 

Race,  illusions  of  the,  158. 

Raehlmann's  cases,  129,  13 1-2,  182. 

Rapport  in  hypnotism,  209. 

Ratio  :  the  "  golden,"  243-4 ;  mathe- 
matical, and  pleasure,  243-6. 

Reaction :  r.  time  and  personal  equa- 
tion, 8;  exps.  on,  38-43;  of  pro- 
tozoa, 161 ;  physical  expression  of 
mental  states,  263-71. 

Reality:  as  test  of  illusion,  111-12; 
character  of  real  space,  155-7; 
social  test  of,  157;  as  interaction 
of  experiences,  158. 

Reason,  lords  it  over  memory,  196- 
7.     See  Intellect. 

Recognition :  in  retention  of  series, 
29 ;  r.-time,  41 ;  affects  sensations, 
loi ;  in  psych,  of  space,  131-5 ;  by 
the  blind,  129-32, 134-5 ;  in  photo- 
graphic negative,  132-2;  with  in- 
version, 133 ;  Indians'  r.  of  music, 
134;  of  music  among  cultivated 
persons,  183;  in  memory,  165-6; 
animals',  191-2. 

Recollection  :  nature  of  the  process, 
71-5 ;  vs.  mere  return,  165,  or  mere 
persistence  of  ideas,  190.  See 
Memory. 

Rectangles,  pleasure  in,  243-4. 

Reflex-action,  and  parallelism,  279. 

Refreshment,  in  harmony,  246-7. 

"  Reins,"  as  seat  of  consciousness, 
271. 

Relations  :  important  for  harmony  of 
senses,  150-1 ;  obscured  by  inten- 
sity of  sensations,  254-5. 

Relativity,  in  comparing  sensations, 
II. 

Religion:  imitation  in,  219;  exp. 
psych,  and,  299-313. 

Rembrandt,  254. 

Reminiscence,  and  art,  191.  See 
Memory. 

Respiration,  and  pleasure-pain,  268. 

Responsibility :  imitation,  hypnotism, 
and,  221-2;  and  psych,  law,  306- 

12. 


Retina :  rate  of  sensations  fi-om,  21- 
6;  antagonism  in,  97;  in  space- 
perception,  135-8 ;  shifting  parts  of, 
138. 

Retinal-image :  why  unconscious  of, 
143;  size  and  inversion  of,  and 
space-perception,  142,  146-8. 

Rhyme,  255. 

Rhythm,  enjoyment  of,  232-6. 

Ring  Cycle,  Wagner's,  257. 

Rods  and  cones,  and  space-thresh- 
old, 126-7. 

Romantic  ideal,  221. 

Royce,  and  imitation,  199,  206. 

Ruben,  Johann,  case  of,  131-3. 

Rubens,  253. 

Ruskinian  fidelity,  violated  by  Na- 
ture, 152. 

Saborski,  178. 

Saints,  their  goodness  available,  219. 

Sanford,  v. 

Savages,  color  preferences  of,  229-30. 

Scholastic  distinction  of  matter  and 
form,  231. 

Schulze,  exps.  on  blind,  etc.,  46. 

Science :  and  evidence,  93-4 ;  vs. 
memory,  195-6;  cannot  cheapen 
life,  311. 

Scripture,  E.  W.,  v,  205. 

Sculpture:  228;  interest  in,  254; 
colored,  257. 

Seat  of  consciousness,  271-5. 

Secretiveness,  seat  of,  274. 

Section,  golden,  243-4. 

Selection,  in  imitation,  223. 

Self-consciousness,  and  imitation, 
218. 

Self-observation,   see    Introspection, 

Sensations:  Weber's  Law,  11;  in 
neural  research,  22;  imperceptible 
differences  in,  26;  psych,  exp.  not 
confined  to,  27-30;  intensity  of, 
48-51;  faint  s.  seem  alike,  87; 
imperceptible,  88-90 ;  influenced 
by  surroundings,  loi ;  are  neither 
true  nor  false,  106;  interpretation 
of,  104, 112-14, 117;  not  enough  for 
truth,   114;     require  our  activity, 


328 


Index 


120;  simultaneity  vs.  extension, 
159;  as  inherently  extended,  160- 
3;  "pure,"  161-2;  supplemented, 
177,  190,  213;  durability  of,  180; 
different  relative  value  of,  180-3; 
modified  by  suggestion,  214-16; 
enjoyment  of,  Ch.  XII,  227-48; 
as  origin  of  mind,  303 ;  as  acts  of 
mind,  305 ;  cerebral  localization  of, 
274-6.  See  Color ;  Music ;  Smell ; 
Sound;  Touch. 
"  Sensations  of  Tone,"  Helmholtz's, 

9. 

Sense-organs:  in  psych,  exps.,  27-30; 
in  illusion,  96-8, 106-8 ;  and  space- 
threshold,  125. 

Senses :  evidence  of,  and  reality,  158 ; 
ranking  of,  179-80;  order  of  de- 
velopment, 275.     See  Sensations. 

Series:  memory  for,  28-9;  mental 
forms  of,  252-3. 

Shadovi^s :  color  of,  43,  214 ;  space- 
judgment,  and  imperceptible,  88- 
90. 

Shakespeare :  rhymed  couplets,  255 ; 
quoted,  216,  270. 

Shinn,  229. 

Shop-window  exp.  in  suggestion,  216. 

Shorthand,  natural  law  as,  284. 

Sidis,  on  hypnotism,  210. 

Sight:  frequency  of  sensations  of, 
21-6 ;  a  compound  sense,  135 ; 
memory  for,  179-80;  and  smell  in 
dog,  183 ;  variation  of  importance, 
183-4;  cerebral  localization  of, 
274 ;  dependent  upon  other  senses, 
274-5;  iJ^  infancy,  275.  See  be- 
low. 

Sight  in  space-perception:  5-6, 
124-5 ;  its  rank  vs.  touch,  127-41 ; 
as  originally  non-spatial,  134; 
retina  vs.  muscles,  135-8;  har- 
mony with  touch,  143-51 ;  discords 
with  touch,  151-2.  See  Color; 
Blind. 

Signal-system,  space-perception  as, 
123,  126-7. 

Size,  in  sight  and  touch,  150-2,  154. 

Skin,  transplanting  of,  138. 


Sleep:  sensations  in,  97;  effect  of 
calling  name  in,  267.  See 
Dreams. 

Smell:  in  animals,  183;  in  infants, 
275;   cerebral  localization  of,  274. 

Society:  social  test  of  reality,  157; 
corporate  memory  of,  196 ;  social- 
ism in  psych.,  157,  221;  and  in- 
dividual, 226,  303-4 ;  social  reform 
and  physiology,  293. 

Socrates,  and  relation  of  soul  and 
body,  291-2. 

Solomons,  on  interaction,  288. 

Sophie  Charlotte  and  Leibnitz,  68-9. 

Sophocles  vs.  Wagner,  257. 

Soul :  simplicity  of,  and  psych,  quan- 
tity, 36;  seat  of,  271-6;  worth  and 
reality  of,  295-314;  "psych,  with- 
out a  soul,"  299-306;  in  psych, 
explanation,  300-2;  sense-impres- 
sions and,  305 ;  mind  and,  305-6. 

Sound :  not  a  compound,  yet  quanti- 
tative, 48;  threshold  of,  79;  con- 
fused with  pressure,  87 ;  subliminal, 
90-1 ;  illusory  intensity  of,  98-9; 
complication  of  color  and,  99-100 ; 
memory  for,  170-1,  173-4,  179-80; 
in  foreign  tongue,  47,  213 ;  subjec- 
tive grouping,  232;  colored,  252; 
emotional  character  of,  259 ;  cere- 
bral localization  of,  274;  without 
power  to  interpret,  275.  See 
Music. 

Space:  spatial  quantity  in  psych., 
51-3;  recognition  hindered,  131-5; 
"real"  s,,  and  illusions,  155-7; 
idealization,  156-7 ;  and  music, 
160;  psych,  beginnings  of,  160-3; 
extension  vs.  simultaneity,  159; 
not  indispensable,  162;  place  of, 
in  mental  life,  164;  memory  for, 
171;  pleasure  in  form,  237-44;  in- 
terest in,  vs.  color,  251-2;  space- 
thinking,  252.     See  below. 

Space-perception :  rank  of  senses  in, 
5-6,  127-141 ;  Berkeley  on,  4-6, 
128-31 ;  threshold  of,  45-7,  124-5 1 
and  imperceptible  shadows,  88-90; 
exps.    on,    particularly   of    blind. 


Index 


3^9 


Ch.  VII,  122-141;  Kantian  vs. 
British  view  of,  122;  and  modern 
geometry,  122,  152;  localization 
in,  122-7 ;  visualists  vs.  tactualists, 
128-41;  of  the  blind,  129-35; 
retina  vs.  eye-muscles  in,  135-8 ; 
pseudoscope,  136 ;  stereoscope, 
137;  telestereoscope,  137;  shifting 
parts  of  skin  and  retina,  138 ;  of 
touch  and  sight :  their  harmonies, 
142-51,  and  discords,  151-2;  non- 
Euclidean,  152-7;  of  protozoans, 
161-3 ;  and  time-perception,  187-8 ; 
vs.  color-perception,  250, 

Speech,  automatic,  76-9. 

Spencer,  6,  122. 

Sphygmograph,  264, 

Spiral,  revolving,  97. 

Spirit,  disembodied,  mental  poverty 
of,  270. 

Spiritistic  view  of  automatisms,  77. 

Spiritual,  the:  vs.  the  sensuous  in 
art,  249;  primacy  of,  undetermined, 
292;  implications  of  exp.  work, 
Ch.  XV,  295-314;  and  common 
psych,  phen.,  305-6.     See  Soul. 

Spurzheim,  9. 

Stars,  angular  discrimination  of,  124. 

Stentor,  exps.  on,  161. 

Stereoscope,  102,  137. 

Stevenson,  70. 

Stoic  ideal,  221. 

Stout,  74. 

Stowell,  A.,  exps.  on  blind,  etc.,  46. 

Subconscious:  phen.,  69,80;  ratios, 
245.    See  Unconscious. 

Subliminal;  s.  stimuli,  and  s.  sen- 
sations, 79-81 ;  s.  sensations,  prob- 
able, 86-88 ;  interruptions  noticed, 
90-1.    See  Unconscious. 

Suggestion:  and  imitation,  Ch.  XI, 
199-226;  at  bottom  the  same  as 
imitation  and  hypnotism,  209 ;  post- 
hypnotic, 211;  physical  effects  of, 
212;  in  sense-perception,  213; 
modifies  sensations,  214-16;  in 
touch,  214;  brief  exposures,  215; 
determines  preference,  216-17 ! 
effect  of,  on  character,  217-8 ;  two 


aspects  of,  220 ;  hindered  by  vivid- 
ness of  impressions,  254-5.  See 
Hypnotism;  Imitation. 

Sully,  on  logic  of  illusion,  108-11. 

Superposition,  illusion  of,  154. 

Surgeons :  their  exps.  on  congeni- 
tally  blind,  5-6,  129-135;  trans- 
planting skin,  138. 

Surprise :  enjoyment  of,  239,  248 ;  in 
life,  308-9. 

Symbols,  spatial,  252-3. 

Symmetry,  pleasure  in,  241-2. 

Sympathy,  in  pleasure  in  lines,  239-40. 

Symphony,  61,  257. 

System  of  experience,  as  test  of  il- 
lusion, 112-14. 

Table-tipping,  205. 

Tabula  rasa  doctrine,  119. 

Tactile  impressions,  see  Touch. 

"  Tactile  Values,"  214. 

Tactualists'  theory,  128-41. 

Tapestries,  color  of,  230. 

Tarde,  and  imitation,  199. 

Tasters  of  wine  and  tea,  175. 

Tawney,  on  suggestion,  214. 

Teaching:  psych,  of  memory,  and, 
184;  imitation  in,  218;  and  nerve 
physiology,  293.    See  Children. 

Telestereoscope,  136-7. 

Temperature,  mistaken  for  pressure, 
87. 

Tennyson,  120. 

Terza  rima,  of  Dante,  255. 

Test :  of  illusion,  108-15 !  social  and 
individual  t.  of  reality,  157-8. 

Testimony,  personal  t.  and  senses, 
215. 

Thecetetus:  sense-perception,  119- 
120 ;  view  of  mind,  304. 

Theology,  and  psych,  quantity,  55. 

Thoughts,  by  machinery,  262.  -. 

Thought-transference,  205,  304. 

Threshold:  meaning  of,  79;  for  all 
senses,  83-4;  absolute  vs.  dis- 
criminative, 86-7. 

Time:  early  exps.,  9;  localization  in 
a  series,  28-9;  temporal  quantity 
in  psych.,  54;   and  imperceptible 


330 


Index 


phen.,  85;  illusions  of,  99;  and  the 
blind,  139-40;  not  linear,  160;  an 
ultimate  process,  164;  memory 
and  the  influence  of,  Ch.  IX,  165- 
84;  mind  in  and  outside  of,  166; 
rate  of  forgetting,  166-9 ;  temporal 
signs,  185-9;  factors  in  t.-judg- 
ments,  186-9;  temporal  fore- 
ground, 187. 

Titchener :  v ;  on  reaction-time,  41-42. 

Tones :  imperceptible  stimuli,  79-81 ; 
threshold  of,  83,  175;  memory, 
173,  178;  preference,  230;  har- 
mony, 245.    See  Music. 

Torrey,  vi. 

Touch:  Weber's  exps.,  lo-ii;  in 
blind  and  normal  persons,  45-7, 
181 ;  threshold,  61,  84-5 ;  confused 
with  sound  and  warmth,  87 ;  rank 
of,  as  space  sense,  5-6,  127-41 ;  in 
vision,,  135-7;  impressions  of,  why 
not  projected,  143;  harmony  with 
sight  as  regards  distance,  143-5, 
direction,  145-9,  size,  150-1 ;  dis- 
cords with  sight,  151-2;  memory 
for,  179-80,  181;  cerebral  localiza- 
tion of,  273 ;  in  infancy,  275. 

Tradition,  as  corporate  memory,  196. 

"Transcendental  -Esthetic,"  Kant's, 

155- 
Transplanting  skin,  138. 
Tree,  and  psych,  quantity,  48-9. 
Trinchinetti's  cases,  130. 
Trinitarianism,  and  psychic  quantity, 

55- 
Tristan  und  Isolde,  66. 
Truth:  prejudiced  by  its  sponsors, 

93;    personal     consequences    of, 

295-6. 
Tschisch,  von,  on  memory,  173,  179, 
Tuke,  Hack,  212. 
Tuning-fork,  tone  of,  230,  248. 

Ugliness,  and  eye-movements,  239- 

40. 
Unconscious,  the :  evidence  for,  Chs. 

IV,  V,  66-94 1  bearings  of  problem, 

66-8 ;  seems  self-contradictory,  68 ; 

Leibnitz  and,  68-9;  alterations  of 


personality,  70-1;  memory  and 
hypnotism,  70-6;  automatic  com- 
munications, 76-9  ;  subliminal 
stimuli,  79-81;  more  favorable 
evidence,  82-91;  u.  ideas  vs.  u. 
materials  for  ideas,  83-94;  proba- 
bility of  u.  sensations,  88 ;  extreme 
views,  92-3 ;  conclusion,  92-4. 

Understanding,  in  memory,  176;  in 
time-judgments,  188-9;  i^^  enjoy- 
ment, 188-9,  248 ;  takes  hfe  out  of 
sensations,  254.    See  Intellect. 

Uniformity  of  mind,  306-7. 

Unitarianism  and  psychic  quantity, 

55- 

Unity:  of  mind,  impressed  by  il- 
lusions, 119;  unity  in  variety,  in 
aesthetics,  249. 

Upright  vision,  146-9. 

Utility:  and  fading  of  sensations, 
180-1 ;  in  evolution,  281 ;  vs.  par- 
allelism, 281 ;  of  mind  for  the  body, 
292. 

Vagueness  :  of  mental  phen.,  56 ;  in 
color-contrast,  58. 

Value :  mental  scales  of,  194-5 1  of 
life,  and  surprise,  308. 

Vase,  eye-movements,  in  viewing,  242. 

Veneration,  seat  of,  273. 

Ventricles,  cerebral,  as  seat  of  soul, 
272. 

Verbal  associations,  and  memoiy, 
29. 

Verse:  rhythm,  233-6;  metrical  ef- 
fects, 255. 

Vierordt,  and  time-sense,  9. 

Violin,  tone  of,  248. 

Virgil,  quoted,  269. 

Vision,  see  Sight. 

Visualists'  theory,  128-4X. 

Voice,  181,  231. 

Volitional  pleasure  in  lines,  239-40. 

Voluminousness,  as  inherent  in  sen- 
sations, 160-3. 
Vorticella,  exps.  on,  161. 

V^agner,  66,  257. 
Wallin,  on  rhythm,  236. 


Index 


331 


I) 


Ward:  on  extension  of  sensations, 
160-3 ;  on  mind  and  body,  291. 

Wardrop,  5. 

Ware,  5. 

Warmth,  confused  with  pressure,  87. 

Weber:  in  history  of  psych,  exps., 
10-13;  law  of  discrimination,  10- 
II,  285 ;  and  Lotze,  15. 
A^ednesday,  symbol  for,  252. 

Weights,  perception  of,  see  Touch. 

Weight-size  illusion,  98. 

Wernicke,  region  of,  274. 

Whispering,  involuntary,  206. 

Wilkinson,  46. 

Will :  an  ultimate  mental  fact,  164 ; 


and  competition  of  ideas,  207 ;  in 
enjoyment  of  lines,  239-40. 

Williams,  9. 

"  Will  to  Believe,"  James's,  211. 

Women,  preference  for  red,  230. 

Wonder,  and  science,  311. 

"  Wonderland,"  Alice's,  107. 

Worlds,  without  illusions,  107. 

Writing,  automatic,  76-9. 

Wundt,  vi.  5,  20;  rank  and  influ- 
ence, 14-15 ;  choroiditis,  138. 

Zollner's  illusion,  52-3. 
Zoneff.  268. 


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